Ronaldo sets up Gunners clash

Needing to become the first English team to beat Porto on their own ground, Ronaldo's amazing 35-yard drive was worthy of achieving that fine feat.

So now old rivals Sir Alex Ferguson and Arsene Wenger must battle it out over two games for the right to go to Rome on May 27.

Ronaldo's sixth-minute effort was his 20th goal of the season and only his second in the Champions League since completing that astonishing haul of 42 in last year's final in Moscow.

He collected Anderson's short pass closer to the halfway line than the opposition goal but sensing, a little trepidation in home ranks, let rip with a shot as brutally powerful as it was audacious in its intent.

Porto keeper Helton did not have a chance of keeping the ball out as it flashed past him to give United the start Ferguson could not have dreamed.

Had Nemanja Vidic been able to keep his close-range effort under the crossbar after John O'Shea had got the faintest of touches to a Ryan Giggs corner just before the interval, the Red Devils would surely have completed their task in half the time allotted.

With Rio Ferdinand back alongside Vidic after his recent groin strain there was an authority about United's defending that had not been in evidence since before they were dismantled by Liverpool five games ago.

There was experience too, with Giggs and Edwin Van der Sar taking just long enough over their set pieces not to incur the wrath of Swiss referee Massimo Busacca while eating up vital seconds.

And while they did not exactly coast home, the visiting supporters were celebrating victory long before the final whistle confirmed it.