Manchester City's Europa League campaign hit a stumbling block last night in Lisbon as a moment of Brazilian magic condemned them to defeat in the first leg of their last 16 match against Sporting.
Defender Xandao netted the only goal of the game on 51 minutes, back-heeling the ball home with his back to goal after keeper Joe Hart had spilt a free kick.
The Premier League leaders were unusually toothless in attack, but will take solace from the fact that they put four goals past Porto - who are 14 points ahead of Sporting in the Portuguese SuperLiga - at the Etihad Stadium in the previous round.
City's night started on a bad note when influential captain Vincent Kompany limped off injured after just seven minutes.
Manager Roberto Mancini had clearly been hoping to rest Joleon Lescott by naming him among the substitutes but that plan was quickly abandoned as it became immediately clear Kompany could not continue.
Sporting spurned several opportunities to take an early lead.
Hart came out of his area to head away a long ball which dipped over Kolo Toure's head and could have been caught out as Stijn Schaars shot from long range but it drifted wide.
Joao Pereira forced Hart to make a smart save as Sporting pieced together a good move and then fired wide moments later.
City had their first serious chance when the ball was worked to Gareth Barry outside the box after a corner in the 24th minute but the England midfielder curled his shot wide.
Sporting broke again as Ricky van Wolfswinkel fed Marat Izmailov in the box but Lescott blocked the Russian's shot.
Dzeko then appeared to hurt himself as he ran into the bench after attempting to keep the ball in play and City might have paid a heftier price had Diego Capel's long-range drive been on target.
City then allowed Daniel Carrico space to try a shot from distance but he too blasted wide.
City looked to make a positive start to the second half but a good break ended when David Silva lofted a shot from Kolarov's driven cross well over.
Sporting responded strongly and took the lead after 51 minutes with a brilliant finish from Brazilian defender Xandao.
Hart could only parry a free kick from Matias Fernandez but did brilliantly to block Xandao's first attempt from point-blank range. Yet he could do little to prevent City falling behind as Xandao reacted quickly and cleverly back-heeled the ball past him.
Hart almost got into trouble again minutes later as he and Lescott failed to communicate as an Izmailov cross came in but the defender headed behind.
City were indebted to Hart just after the hour when he saved low down from Van Wolfswinkel eight yards out.
Mancini brought on Mario Balotelli in the place of Edin Dzeko with 19 minutes to go and the Italian striker - recently fined a week's wages for a recent late night out - did inject some extra spark into the City attack.
Kolarov's cross dropped on to the crossbar and Lescott powered a header against the woodwork - though the whistle had already blown for a free kick - as City pressed to no avail late on leaving them with work to do in the return leg next week.