MANCHESTER - Watching Manchester United beat Inter Milan 2-0 to reach the Champions League quarter-finals on Tuesday was like being on suicide watch, manager Alex Ferguson said. United remained on course to retain their title but were severely tested by Inter, who twice hit the woodwork and threatened to score an away goal which could have turned the tie their way following a 0-0 draw in the first leg in Italy. "It was one of those long European nights when you don't know whether you are watching a game of football or watching a game of suicide," Ferguson told reporters. "After scoring the first goal I thought we could go on and kill the game but once we started putting the icing on the cake we opened the door for Inter and we were lucky to be in front at halftime. "I thought it could have been one of those nights when we would maybe score a few goals but then we started to do flicks and back-heels. It was practice football that allowed Inter to get a grip of the game from the middle to the end of the first half when they were the better team," he said. "But we were better in the second half. There was a period when we played more like a European team and our defensive performance was fantastic. (Rio) Ferdinand and (Nemanja) Vidic were brilliant." Ferguson said the result, sealed with headed goals from Vidic and Cristiano Ronaldo early in each half, would stand United in good stead as they bid to reach the final in Rome. "I thought it was a difficult draw, given the experience they've got, and I am happy to get through it and now we can look forward to the quarter-finals," he said. "I think we will be better in the next round. We can play better than that."