But Porto continued to play their game, and looked the better side in the first half, creating 10 shots on goal versus 4 from the home team.

Alex Ferguson’s men improved their performance after the break, and it seemed substitute Carlos Tevez gave Man U the win, scoring at the 85 minute mark. But Porto had a sub of their own, Mariano Gonzalez, who collected the ball at the far post after a deflected cross by Raul Meireles, and put the ball in the net for a 2-2 tie.

Now, even a 1-all draw at home on April 15 will be enough for Porto to create the biggest sensation of the quarterfinals. And the Man U camp understands the tough task that lies ahead of them.

"Well, it's a difficult job now I agree, not made any better when they tell you no British team has ever won in Porto, so we have a job to do," said Sir Alex Ferguson, Manchester United manager.

Villarreal 1-1 Arsenal

Marcus Senna put the hosts in front after 10 minutes, delivering a great shot from 25 meters past goalkeeper Manuel Almunia to make the score 1-0.

It seemed Arsenal needed a miracle to come back into the game after losing both Almunia and leading defender William Gallas through injuries. But the miracle came in the face of a brilliant overhead effort from striker Emmanuel Adebayor to equalize at 1.

The valuable away goal makes the London team look confident coming into the second round.

"In the second half, we had a great response and took completely over and managed a great equalizer. it puts us in a great position, but of course we want to qualify at home," said Arsene Wenger, Arsenal Manager.