Porto's South American connection came up with the goods with a spectacular volley from Argentine international Lucho Gonzalez followed up by a goal from compatriot Lisandro Lopez.

Hamburg hit back with Dutch international Rafael van der Vaart scoring a minute after Lopez's goal, but Brazilian Bruno Moraes scored three minutes from time to clinch the win for the Portuguese visitors.

Porto are now level on seven points with Arsenal, who drew 0-0 with group leaders CSKA Moscow on Wednesday.

For Hamburg, playing in this competition for the first time since 2001, it has been a brief European adventure with four straight defeats meaning they do not even have a chance to qualify for the UEFA Cup with third place.

"We worked hard for an entire year to come up against the best teams in Europe and we have let ourselves and the whole of German football down with our performances," fumed Hamburg coach Thomas Doll.

"Four defeats in four games shows we have not performed in this competition.

"I am not willing to put the blame solely on my team as I must take some responsibility."

Van der Vaart returned in midfield for the hosts after two months out through injury and Argentina captain Juan Pablo Sorin shrugged off a niggling injury to start.

Porto were without their 18-year-old midfielder Anderson, injured in the league match with Benfica over the weekend, but started the stronger with Raul Meireles's fierce drive stinging the palms of Sascha Kirchstein.

With 16 minutes gone Portuguese international Helder Postiga spurned Porto's best chance firing over the crossbar after some fine one-touch passing split Hamburg open.

The home fans were beginning to get on Hamburg's back but livened up in the 20th minute when Danijel Ljuboja, who gave away a stupid penalty in the first match between these two teams, forced a great save from Helton with a downward header.

A moment of magic opened up the game with former River Plate midfielder Gonzalez striking a sensational 20 yard controlled volley that was in the net before Kirchstein could dive.

Minutes into the second half Postiga should have wrapped up the match after some woeful defending but shot straight into the arms of Kirschstein.

Porto had crushed Hamburg 4-1 in the home fixture and were once again too strong and the underworked Helton was even getting involved in the build-up play coming out of his penalty area.

In the 61st minute Porto doubled their lead with Lisandro Lopez pouncing on a centre from Ricardo Quaresma.

Van der Vaart pulled one back a minute later with a rare header and in the 65th minute the hosts hit the post as Porto wobbled.

However Brazilian Moraes curled a sweet left-footed shot into the corner late on to ease their nerves and they now go into their next match at group leaders CSKA Moscow on November 21 full of confidence.