Porto 0-1 Manchester United (2-3 on aggregate)

Cristiano Ronaldo has claimed the best goal of his career can be the catalyst that fires Manchester United towards three more trophies this season. Ronaldo's stunning strike after six minutes sealed a 1-0 win over Porto last night, which earned a 3-2 aggregate triumph and set up a semi-final with Arsenal for the holders.

The Gunners have the edge over United this season, having triumphed 2-1 in the Premier League at Emirates Stadium in November in the only meeting between the sides so far in 2008/09, but Ronaldo believes United are back on track for a clean sweep of five trophies after knocking out Porto.

The European and World Player of the Year said: “We have an opportunity to win everything and we are very confident that we can.

“We did not play fantastic in the last five or six games but we expect the next ones will be better because of what we did last night. The goal was the best I have scored.

“It was a fantastic strike and I am very happy with it. It is going to be a fantastic tie against Arsenal, because they play great football. I just hope we can win and go through to the final.”

United were the first English club to beat Porto at the Stadio do Dragao, a result they needed after managing only a 2-2 draw with the Portuguese champions at Old Trafford last week.

Sir Alex Ferguson's men will again enjoy home advantage in the first leg in the double-header against the Gunners and the United boss warned his players they must make it count.

Ferguson said: “It would have been tough no matter who we played but the fact it is another English side gives a different type of spice to it.

“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.”

Although Ronaldo's displays this season have rarely matched his scintillating performances last term, the 24-year-old's ability to make decisive contributions in vital matches is a major weapon for United. His early goal destroyed Porto's confidence and United's defence — who have looked shaky in recent domestic matches but were boosted by the return of Rio Ferdinand — were rarely troubled.

Ferguson admitted: “I will have to trawl a long way back through my memory bank to come up with anything as good as that goal.

“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. They boys played well. We had good control at the back and that is always key.

“When you have the stability of Rio Ferdinand and Nemanja Vidic, it is a big help. That may have been missing in recent games. Rio and Nemanja 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 the back four.”

The first leg against Arsenal is on
29 April, with the decisive fixture at Emirates Stadium six days later.

Indeed, the next 19 days will be hugely important for United's season. They face Everton in the FA Cup semi-final at Wembley on Sunday, before taking on Portsmouth and Tottenham in the League at Old Trafford on 22 April and 25 April respectively.

The matches against Arsenal come either side of a Premier League trip to Middlesbrough on 3 May. As well as having the chance to seal a place in two major cup finals, therefore, United also know that three straight League wins may carry them a long way to a third successive League title.

Yet even though he is in contention to win five trophies with United, Real Madrid's former president Ramon Calderon has again insisted Ronaldo will move to the Bernabeu this summer.

He said: “The next president will have at his disposal one of the best players in the world, who is already committed to Real.”