Tiago put the visitors ahead inside the opening few minutes but Bosko Jankovic levelled eight minutes before the interval.

The result leaves both sides on 11 points from six games, five points behind the Poles who have played one game more.

The visitors, who thrashed Belgium 4-0 on Saturday, started with the swagger of a side full of confidence.

And that was best demonstrated by Tiago's stunning opening goal after five minutes - the Lyon midfielder cleverly lobbing home keeper Vladimir Stojkovic from 35 yards.

Serbia slowly worked their way back into the match but Portugal were dangerous on the break and Armando Petit almost made it 2-0 with a drilled effort which flew just over the bar.

It took 18 minutes for Serbia to test Portugal keeper Ricardo, the visiting custodian alert to keep out Dusko Tosic's 12-yard shot.

But Portugal came again and they ought to have doubled their lead after 25 minutes but Nuno Gomes somehow managed to head Simao Sabrosa's outswinging corner over from six yards.

At the other end, Nemanja Vidic's physical presence was causing the Portuguese defence problems and the Manchester United defender nodded wide from close range shortly before the half-hour mark.

It proved to be a sign of what was to come from the hosts as they dragged themselves level after 36 minutes when Dejan Stankovic's corner was headed home by Jankovic.

Nuno Gomes almost replied immediately but his 12-yard shot flashed wide.

Cristiano Ronaldo was the architect of Portugal's demolition of Belgium with two goals and the talented winger came close to getting on the scoresheet once more only for his shot to be superbly blocked by Igor Duljal on the stroke of half-time.

Portugal also started the second half on top with Joao Moutinho firing in a shot which produced a fantastic save from Stojkovic.

Stojkovic excelled himself again after 64 minutes to deny Tiago his second of the evening.

And he completed a fine individual performance by parrying clear Ronaldo's powerful free-kick with 16 minutes to go.