Tito Vilanova returned to the Barcelona bench for the Catalan derby against Espanyol - but admitted his cancer battle is not yet over and he may be forced to step back from the club once more,
The 44-year-old underwent surgery for a second time on a tumour on a saliva gland on December 20.
He missed the away win over Valladolid but was back in the Camp Nou dugout on Sunday for the 4-0 derby victory which allowed Barcelona to go 11 points clear of Atletico Madrid and 16 ahead of bitter rivals Real Madrid.
"This is not over yet and there will be days that I can take training and others I can't but I want the media to realise that this illness is mine and it is private even if I am a public figure," said Vilanova.
"I would like to thank everyone for their support. This club has had a lot of knocks in the last couple of years but I always want to take the positive approach. What has happened to me could have happened to anyone."
Barcelona had scored all of their goals by the half-hour and after that it was procession football, with Pedro twice denied a hat-trick by the offside flag while other chances also passed.
After Xavi had opened the scoring, Pedro then chimed in with his brace before Lionel Messi added a penalty.
The win leaves Barcelona 11 points clear at the summit after nearest challengers Atletico Madrid could only draw 1-1 at Real Mallorca.
Raul Garcia broke the deadlock in the 72nd minute for an Atletico side sheared of star striker Radamel Falcao due to suspension, and Mallorca punished the visitors' inability to see them off as Kevin Garcia popped up with an equaliser three minutes from time.
Third-placed Real Madrid stay 16 points behind Barca after defeating Real Sociedad 4-3 - despite playing for 84 minutes with 10 men.
Karim Benzema had swept the champions into the lead after 90 seconds but Jose Mourinho's decision to once again leave goalkeeper Iker Casillas on the bench backfired six minutes in as replacement Antonio Adan brought down Carlos Vela inside the area and was sent off.
Xabi Prieto slotted home the penalty, and both sides exchanged further goals before half-time as Sami Khedira put Madrid back in front only for Prieto to level five minutes later.
Cristiano Ronaldo looked to have sealed the points with two goals in two minutes midway through the second half, but Sociedad were given another lifeline when Prieto completed his hat-trick with 15 minutes remaining.
The visitors themselves were reduced to 10 men on 80 minutes as Dani Estrada was shown a second yellow card for bringing down Ronaldo and the Basques failed to muster another effort on goal.
Mourinho said after the game that he was unconcerned by abuse directed at him from the crowd.
"Let them whistle me before the match and then support the team as they are doing," he said.
"I think the whistles are for leaving Casillas out and also because we are not achieving our aims in the championship," he said.
"There are others who didn't applaud and are not happy with his performances. If I am not doing well it is normal that they whistle and it is something you have to live with. I don't want to be a hero independently of my performances."
In the day's early kick-off, two goals from Iago Aspas and a wonderful strike from Alex Lopez were enough to hand Celta Vigo a 3-1 win over Valladolid.
Aspas enhanced his burgeoning reputation with a fine run and finish after eight minutes, but Valladolid were level moments later when Alberto Bueno converted from the spot after Javi Varas had brought down Javi Guerra.
Aspas restored the lead with a penalty of his own on the half-hour and Lopez sealed the points seven minutes into the second half with a brilliant strike from 25 yards.
Title hopefuls Juventus started the new year in a less than convincing fashion as they were beaten 2-1 at home by 10-man Sampdoria.
Knowing a win won restore their eight-point cushion over Lazio, Juventus were undone by a brace from Mauro Icardi.
Sebastian Giovinco`s early penalty had put them ahead, and when Gaetano Berardi was sent off, it looked to be a stroll for Juventus, but Icardi had other ideas.
Napoli are third, seven points behind, after a 4-1 drubbing of Roma.
Edinson Cavani was the star of the show, displaying why he is one of the most sought-after players on the planet, scoring a brilliant hat-trick to see off the 10-man capital club.
Cavani scored either side of half-time and soon made it eight from 11 appearances against Roma.
Pablo Osvaldo did pull one back, but Miralem Pjanic was then sent off and Christian Maggio added a fourth.
"I'm happy to be taking the match ball home after this hat-trick," Cavani told Sky Italia after the match.
"It was a great performance by everyone tonight and helps put our recent poor spell behind us. We've shown that we can be professional and fight for important objectives this season."
Juventus were not the only side to miss a trick as Fiorentina, sitting in fourth, lost 2-0 at home to struggling Pescara.
Mattia Perin kept La Viola at bay throughout a one-sided first-half, but in the second period goals from Jonathas and Mervan Celik turned things around.
Inter Milan also found their luck had run out as they were humbled 3-0 at Udinese, with their performance a far cry from the form they had displayed in the months leading up to Christmas.
Antonio Di Natale was on target twice with Luis Muriel also scoring for Francesco Guidolin's side, who were aided by a red card for Juan Jesus in the 65th minute.
AC Milan were able to take advantage of the slow movers above them, closing the gap on the top six thanks to a 2-1 win over Siena.
Second-half goals from Bojan Krkic and Giampaolo Pazzini earned the Rossoneri the points with Michele Paolucci scoring a late consolation for the Tuscans, who remain rooted to the foot of the table, six points adrift of safety.
Elsewhere, Isaac Cofie's first goal for Chievo settled a narrow 1-0 victory over Atalanta that keeps them in the hunt for a top-half finish, and Marco Borriello struck a second-half brace to help Genoa down fellow strugglers Bologna 2-0 and claim only their fourth league win of the season.
In the day`s other game, a last-gasp goal from substitute Amauri condemned his former club Palermo to another defeat at Parma, the home side winning 2-1.
Relegation-threatened Palermo had failed to win in seven previous visits to the Stadio Ennio Tardini, mustering only four draws, and they were never ahead, but a refreshed line-up caused Parma plenty of trouble on the counter-attack.
Parma survived their visitors' early enthusiasm to snatch the lead through Ishak Belfodil midway through the second half but Igor Budan pegged his former employers back with an equalising header.
Amauri would have the last word, though.
Benfica head the Liga table by three points from Porto after a 3-1 win at Estoril.
Having seen Porto beat Nacional 1-0, Jorge Jesus' men responded at the Estadio Antonio Coimbra da Mota, opening up a three-goal lead through Nicolas Gaitan (37), Rodrigo Lima (59) and Eduardo Salvio (66).
Estoril scored a consolation through Goncalo Santos (88) but by then it was too late.
Braga are third in the table after Antonio Eder scored the only goal of the game 11 minutes after the break as they got the better of Moreirense.
The day's other game saw Maritimo draw 1-1 at home to Beira Mar, with Philipe Fidelis (58) cancelling out Serginho's 52nd-minute opener for Ulisses Morais' men.
Lowly Epinal stunned joint Ligue 1 leaders Lyon to dump them out of the Coupe de France on penalties in the ninth round.
Famara Diedhou scored the winning penalty as Epinal, struggling in the drop zone of France's third tier, won the shoot-out 4-2, with the match having finished 3-3 after extra-time.
Epinal stunned the visitors as Tristan Boubaya scored in the 10th and 13th minutes to power them into a 2-0 lead, although Lyon were level by the 20th minute as Bafetimbi Gomis and Gueida Fofana replied in a thrilling start to the match.
Lisandro Lopez fired Lyon ahead from the penalty spot soon after the hour mark after Valentin Focki handled, but Focki made amends with a 75th-minute equaliser that sent the game to extra-time.
The 30 minutes passed without further goals, but misses from Fofana and Sidy Kone in the shoot-out cost Lyon the chance to progress.
Marseille, level with Lyon and Paris St Germain at the top of the league table, needed an extra-time winner from Andre-Pierre Gignac to sneak past Ligue 2 side Guingamp with a 2-1 win at the Velodrome.
Gignac had given L'OM a 23rd-minute leader but they could not add to their advantage before Christophe Mandanne levelled seven minutes from time.
That forced the extra period which Marseille edged when Gignac struck his second in the 107th minute.
Nice needed extra-time to beat Metz 3-2 away from home, despite the hosts playing from the 22nd minute with only 10 men following the dismissal of Gregory Proment.
Proment was somewhat harshly dismissed for a foul on Didier Digard after 22 minutes and Nice soon took advantage with Neal Maupay firing home.
But they failed to take advantage and Yeni N'Gbakoto levelled early in the second half, sending the game to extra time.
Valentin Eysseric struck twice in the 98th and 107th minutes to put Nice in control, and Thibaut Bourgeois' 114th-minute effort was in vain.
Ligue 2's Lens knocked out top-flight Rennes 2-1 courtesy of a late own goal from Kevin Theophile-Catherine.
Just six minutes after Julien Feret had cancelled out Jerome Le Moigne's first-half opener, Theophile-Catherine put through his own net in the 87th minute.
Bordeaux needed an injury-time winner from Brazilian defender Mariano to top Ligue 2's Châteauroux 3-2 away from home, despite the hosts playing with 10 men for most of the second half.
Fahid Ben Khalfallah put Bordeaux ahead before the half-hour mark, but Châteauroux shrugged off the dismissal of Elie Ehua early in the second half to snatch the lead through Claudio Beauvue and Kevin Afougou.
But Henrique levelled after the hour mark before Mariano nicked it.
St Etienne saw off Ligue 2 Caen 3-2 as Joshua Guilavogui scored either side of a Kevin Mayi strike, with Faycal Fayr registering a brace for the hosts.
First-half goals from Souleymane Camara and Emmanuel Herrera set up a 2-1 away win for Montpellier over National side Bourg-Peronnas.
Ligue 2 strugglers Sedan needed an injury-time winner from Mickael Le Bihan, his second, to beat Pontparlier 2-1 away, but fellow Ligue 2 side Arles-Avignon were knocked out by lowly Mende 2-0.
Meaux beat Le Portel 1-0 while Fontenay-le-Comte were 2-0 winners at Muret.
Paris St Germain were given a huge scare by amateur side Arras before eventually booking their place in the next round with a 4-3 victory.
PSG coach Carlo Ancelotti rested a number of his big names, including Zlatan Ibrahimovic, but the capital club looked comfortable as they raced into a 2-0 lead inside 10 minutes thanks to Ezequiel Lavezzi and Blaise Matuidi.
Arras pulled one back in the 26th minute through Moustapha Ait-Bouhou, before Zoumana Camara added PSG's third in the 40th minute.
Arnaud Despres got a second goal for the hosts in the 52nd minute to set PSG nerves jangling again until Lavezzi's second in the 68th minute restored their two-goal cushion.
Sebastien Bernard struck Arras' third with nine minutes remaining but PSG held on.
Ligue 1 Bastia suffered a huge shock as they went down to a 2-0 defeat at neighbours CA Bastia, the amateur side earning local bragging rights thanks to an Alassane Ndiaye strike and a Sylvain Marchal own goal.
Brest needed penalties to see off Lucon after a 1-1 draw, while Nantes were 3-2 winners away to Dieppe.