Ronaldo: Winning goal my best

Cristiano Ronaldo claimed the wonder goal that took Man United into the semi-finals was the best of his career.

Ronaldo struck after just six minutes, drilling home an incredible effort from fully 35 yards to set up a last-four duel with old rivals Arsenal.

The Portugal superstar's 20th goal of the season was worthy of winning any game. And Ronaldo admitted he had never scored a better one.

"It is the best I have scored," he said.

"It was a fantastic strike and I can't wait to see it again on DVD. I am very happy with it."

The goal put Porto on the back foot almost immediately.

And, although United were forced to survive a few scary moments as the home side desperately tried to find a way through at the end, Sir Alex Ferguson was never seriously concerned his side would lose their precious lead.

It means, for the first time, United must face English opposition in a two-legged European tie, with old rival Arsene Wenger lying in wait for a battle to decide who will go to Rome for the final on May 27.

"It would be tough no matter who we played but the fact it is another English side gives a different type of spice to it," said Ferguson.

"We are two good footballing sides, so it should be a terrific semi-final.

"Our game earlier in the season was fantastic. It was the way football should be played and we will look forward to it.

"The first leg is at home, so 1-0 would be perfect for us. But it is not going to be easy."

Champions League Wednesday in pics!

There was a purpose and focus about United from the first whistle.

It resulted in a performance far removed from the below-par efforts of recent weeks, including last week's first leg, with Ferguson confirming the return of Rio Ferdinand after a recent groin strain was a key factor.

"Rio coming back was a major part of our success," said the United boss.

"He and Nemanja Vidic have a partnership that goes back three years. They have a great understanding of the game and there is a good balance between them.

"Rio coming back allowed us to cement a back four to what it really is. They performed really well tonight."

The contributions of Wayne Rooney and Ryan Giggs, whose energy belied his 35 years, were also crucial, as was the secure goalkeeping of Edwin van der Sar.

But, as Ferguson acknowledged, none of it would have mattered without the contribution of Ronaldo, whose 20th goal of the season - and only his second in the Champions League since last year's final - was enough to inflict Porto's first defeat on home soil against English opposition.

"I will have to trawl a long way back through my memory bank to come up with anything as good as that," said Ferguson.

"It was a sensational goal. It was a great strike and to do it so early gave us the platform to go on and win.

"It put them on the back foot and I really don't think they had a chance after that."