Cristiano Ronaldo double seals Nations League quarter-final berth for Portugal

Ronaldo stars in 5-1 thrashing of Poland, Scotland and Spain secure wins

Portugal's Cristiano Ronaldo, centre, celebrates after scoring his side's fifth goal in the Nations League match against Poland at the Dragao Stadium in Porto. AP

Cristiano Ronaldo was back to his best as he scored twice to help Portugal secure a Nations League quarter-final berth following a 5-1 thrashing of Poland on Friday.

Rafael Leao broke the deadlock just before the hour with a header before Ronaldo doubled the lead from the spot in the 72nd minute with a confident strike down the middle of the goal.

The hosts then scored three goals in eight minutes through Bruno Fernandes, Pedro Neto and Ronaldo's clever strike before Dominik Marczuk got a consolation for Poland in the 88th.

"The first half was very bad for what we wanted to do, we lost focus and got frustrated. But the second half was the best I've seen," said Portugal coach Roberto Martinez.

"We've changed the mentality and increased the intensity and mutual support. We didn't let Poland play."

Poland were the better side early on but failed to take their chances in Porto and the home side made them pay, netting four times in the last 20 minutes.

"We couldn't impose ourselves on the game in the first half," said Portugal goalscorer Leao.

"(Coach) Roberto Martínez's approach in the locker room was important; it was the key to changing the pressure at half-time."

Ronaldo volleyed over from close range shortly before the interval, as Portugal failed to register a shot on target in the first half.

Marczuk almost broke the deadlock in the 58th minute, but Portugal goalkeeper Diogo Costa produced a brilliant fingertip save to deny him.

The hosts broke from the resulting corner to score less than 60 seconds later, as Leao powered forward before finding Nuno Mendes, then continuing his run to meet the PSG full-back's cross with a powerful header.

Portugal were awarded a penalty when Diogo Dalot's strike flicked off Jakub Kiwior's hand at point-blank range and was saved by Marcin Bulka.

Ronaldo stepped up to dink home a 'Panenka' spot-kick.

That goal ended any hopes Poland had of staging a comeback and Fernandes added a third for Portugal with 10 minutes left, crashing the ball in off the crossbar from just outside the box.

Neto also got on the scoresheet, collecting Ronaldo's pass and rifling past Bulka at his near post.

There was still time for Ronaldo to double his tally and move onto 135 international goals, acrobatically volleying home Vitinha's cross from close range in the 87th minute.

Portugal remained unbeaten to top the group with 13 points, six ahead of Croatia, who lost 1-0 away to a Scotland side who are still bottom but now level on four points with third-placed Poland.

Poland host Scotland on the final matchday on Monday while Portugal travel to Croatia.

Scotland and Spain shine

In the other match in the group, Scotland gave their hopes of avoiding the drop a massive boost as John McGinn scored a late winner in a 1-0 victory over 10-man Croatia.

Petar Sucic was sent off in the first half, but Croatia almost hung on for the point they needed to qualify with Portugal, only for McGinn to strike in the 86th minute.

European champions Spain stayed unbeaten in Group A4 with a 2-1 win over Denmark in Copenhagen.

John McGinn of Scotland celebrates scoring his team's first goal in the Nations League match against Croatia at Hampden Park. Getty Images

Luis de la Fuente's visitors started strongly and went close to a 13th-minute opener when Ayoze Perez rattled the crossbar.

Spain took an early lead after Denmark carelessly gave the ball away on the edge of their own box.

Perez played in Mikel Oyarzabal who took an excellent first touch and slipped the ball past goalkeeper Kasper Schmeichel and in at the near post.

Villarreal forward Perez doubled Spain's advantage with a low, left-footed finish into the bottom corner after being picked out by Dani Olmo.

Gustav Isaksen pulled one back for Denmark late on, pouncing on a terrible mix-up between Fabian Ruiz and 'keeper David Raya.

"A very, very happy night for me (with a goal and an assist), but the most important thing is going through top of the group," Perez said.

The other game in Group A4 saw Switzerland relegated by Aleksa Terzic's late equaliser in a 1-1 draw with Serbia.

Meanwhile, the match between Romania and Kosovo in Bucharest was abandoned in stoppage time after the visiting players walked off the field when they heard pro-Serbia chanting from the home fans.

With the match heading for a goalless draw, the Kosovars headed for the dressing room in the 93rd minute after home fans chanted, "Serbia! Serbia!" during a heated exchange between Kosovo captain Amir Rrahmani and Romanian striker Denis Alibec.

The match was initially suspended before being abandoned when the Kosovo team refused to return to the pitch. Uefa said it would communicate "further information in due course".