European champions Portugal got their Euro 2020 qualifying campaign back on track with goals from William Carvalho, Goncalo Guedes, Cristiano Ronaldo and Bernardo Silva helping them to a pulsating 4-2 Group B victory in Serbia on Saturday.

The victory lifted the Portuguese to second place in the group on five points from three games, eight behind runaway leaders Ukraine who have 13 from five matches after their 3-0 win in Lithuania earlier on Saturday.

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Third-placed Luxembourg and Serbia in fourth both have four points from as many games while Lithuania are bottom with one point from four matches.

Portugal dominated the opening half and Carvalho fired them ahead in the 42nd minute when he poked the ball into an empty net from three metres after Serbia keeper Marko Dmitrovic spilled a Bruno Fernandes cross from the right.

Ronaldo, looking subdued in the opening half and given a hostile reception at Red Star stadium as Serbian fans jeered him every time he touched the ball, twice came close early in the second half.

He fired inches wide from the edge of the penalty area after cutting in from the left and then curled a free kick narrowly off target before Guedes doubled Portugal's lead with a fine individual effort.

The forward capped a flowing move as he sidestepped a defender and rifled in an unstoppable shot past Dmitrovic into the far corner from 12 metres to silence the raucous home crowd.

Centre back Nikola Milenkovic pulled one back for Serbia in the 68th minute, heading a Dusan Tadic corner past keeper Rui Patricio, who was two minutes later forced to tip a fierce Adem Ljajic shot from 20 metres over the bar.

Taunted by chants of "Messi" from Serbia's die-hard fans, Ronaldo demonstrated his class in the 80th minute when he took a Bernardo Silva pass in his stride and coolly dinked the ball over the advancing Dmitrovic.

Serbia refused to roll over as Aleksandar Mitrovic drove a shot from inside the penalty area into the roof of the net after a defensive blunder in the 85th minute but Silva sealed the contest with a clinical finish barely 60 seconds later.