Portugal claimed their third successive win in European Championship qualifying Group I by edging out Serbia at Estadio da Luz.
Veteran defender Ricardo Carvalho headed the hosts into an early lead in Lisbon although Nemanja Matic's outstanding overhead volley levelled matters just after the hour mark.
But the score would not remain level for long as Fabio Coentrao finished from close range following a quick break by the Portuguese, who claimed a 2-1 victory to go top of the pool by two points ahead of Denmark and Albania.
Fernando Santos' men began their campaign with a shock defeat at home to Albania but they have responded superbly since with wins over Denmark, Armenia and now Serbia.
They started brightly and took a 10th-minute lead when a short corner allowed Coentrao to cross to an unmarked Carvalho and the 36-year-old Monaco defender made no mistake by heading home.
Chelsea midfielder Matic headed over from a corner, while at the other end Portuguese talisman Cristiano Ronaldo's strike from all of 35 yards produced a fantastic save from Vladimir Stojkovic.
The Serbia goalkeeper was called into action shortly before the interval when Tiago headed on from a free-kick.
Serbia were finding chances few and far between from open play but were proving a threat at set-pieces and Matic equalised from a corner in spectacular style in the 61st minute.
Aleksandar Kolarov's centre was headed towards the back post, where Matic set himself and his acrobatic overhead kick left Portuguese keeper Rui Patricio with no chance.
The lead lasted just two minutes though, as Portugal counter-attacked to excellent effect, with Coentrao tapping home at the back post from Joao Moutinho's teasing low ball into the area.
Neither side threatened from then on as Portugal were happy to soak up the pressure in the closing stages and preserve their lead, with Serbia unable to create anything meaningful.