MANCHESTER, England (AP)

FC Porto and Arsenal scored crucial away goals yesterday, giving both teams the advantage heading into the second leg of the Champions League quarter-finals next week.

Porto got a late equaliser from substitute Mariano Gonzalez in its 2-2 draw at defending champions Manchester United, and Emmanuel Adebayor scored in the second half to give Arsenal a 1-1 draw at Villarreal.

The second legs will be played April 15, and the winners will play each other next month in the semi-finals.

Gonzalez scored Porto's equalising goal in the 89th minute, four minutes after Carlos Tevez had put United ahead 2-1 at Old Trafford. Lucho Gonzalez's cross from the right was left by Gary Neville and Mariano brought it down with his chest before shooting past United goalkeeper Edwin van der Sar.

"Getting the goal the way they did we should really have defended that. It was a bad goal to lose," United manager Alex Ferguson said. "It will be a difficult game now over in Porto without question."

Poor clearance

Tevez thought he had given United the lead for good only minutes earlier, lifting the ball into the net when Wayne Rooney's heel flicked on Neville's throw-in.

In the first half, United trailed for the first time in their title defence in the fourth minute when Jonny Evans' poor clearance allowed Cristian Rodriguez to put Porto ahead. But the visitors also had some sloppy defending, and Rooney took advantage of it to equalise in the 15th by pouncing on a lax backpass from Bruno Alves.

Adebayor chested

Arsenal got their away goal in the 66th minute when Adebayor chested a long ball from Cesc Fabregas to the right of the area and beat Diego Lopez with a bicycle kick.

Villarreal had taken the lead in the 10th when Marcos Senna's swerving shot from 20 metres evaded diving goalkeeper Manuel Almunia and landed inside the top corner.

In the 70th, Robert Pires came on to face his former team for the first time since leaving London in 2006, and Villarreal began to respond with better chances. Guille Franco, however, missed two good chances in the last 10 minutes and Senna sent a hard shot toward goal in the 80th, but is just missed the top corner.

Arsenal may have the advantage heading into the second leg, but the English team may have to play without defender William Gallas.

The France international could be out for the rest of the season after damaging knee ligaments in the first half. He went down after colliding with Villarreal striker Giuseppe Rossi late in the first half and stayed on the field for several more minutes before limping off and being replaced by Johan Djourou in the 43rd.

Today five-time European champions Liverpool will host Chelsea in the first leg of the quarter-finals, while Bayern Munich visit Barcelona. The second legs will be played next Tuesday. The final is scheduled for May 27 in Rome.