[UEFA CHAMPIONS LEAGUE] Even with a bad knee, Wayne Rooney was once again too much for AC Milan. The England striker scored once in each half to give him four goals in two games against Milan -- and 30 on the season -- and lead Manchester United to a 4-0 win on Tuesday at Old Trafford in the second leg of their UEFA Champions League series.

Rooney scored on a header and after being brilliantly put through by Nani before going off.

Afterward, United manager Alex Ferguson challenged Rooney to match the 42 goals scored by Rooney's former teammate, Cristiano Ronaldo, two seasons ago.

“It’s a challenge [for Rooney to get 42 goals]," Ferguson said. "I was just happy for him to reach 30, to be honest with you. But he keeps on improving and he was sensational again tonight. He is still carrying an injury, nothing serious, but with a game on Sunday [against Fulham] we wanted him off early. His performance was a continuation of his form over the last two or three months, just sensational, unbelievable. I’m very pleased with him."

(The United record for goals in a season is 46, set by Denis Law in 1963-64.)

Park Ji-sung and Darren Fletcher later added goals to make the final aggregate score 7-2 in United's favor.

“It was an impressive night for us,” Ferguson said. “When we play at that tempo, we’re difficult to play against and it was a really solid performance.

In his Old Trafford homecoming, David Beckham had Milan's best chance, a volley Edwin van der Saar did well to save.

Afterward, Beckham wore one of the green-and-gold protest scarves (the colors of Newton Heath, United's original incarnation) in apparent support for United fans trying to force the Glazer family to sell the team.