Manchester United became the first English team to win in Porto as they progressed into the semi-finals of the CL with a 1-0 win. Arsenal will now be Manchester United's opponents in the Champions League semi-final after a 35 yard scorcher from Ronaldo.

The Reds deserved their 3-2 aggregate victory and could have made the result more comfortable had Nemanja Vidic and Dimitar Berbatov taken their chances.

United almost paid the price late on as Porto went close through Lisandro Lopez but his shot was weak and Edwin van Sar saved.

United boss Sir Alex Ferguson felt his defence was key to the triumph.

He told Sky Sports: "They did well. We showed good concentration at the back and defended very well.

"If we get back to that foundation of not conceding goals, we can do well. We had stability at the back with the recognition of Ferdinand and Vidic and that was a great start.

"I couldn't see the dangers. I thought we controlled that part very well. Nothing really bothered us."

Ronaldo's goal was a superb strike from fully 40 yards.

"It was a magnificent goal, a fantastic hit," continued Ferguson. "It took them by surprise, the keeper had no chance."

United will now face Arsenal in the last four, and Ferguson added: "It's going to be a great semi, there'll be some good football in that one."