Filed at 5:52 p.m. ET

ROME (AP) -- Cristiano Ronaldo soared to head in Paul Scholes' cross in the 39th minute, Wayne Rooney added a second-half goal and Manchester United defeated AS Roma 2-0 Tuesday night in the first leg of the European Champions League quarterfinals.

Ronaldo dashed toward the net and leaped for his seventh Champions League goal of the season, moving ahead of Barcelona's Lionel Messi at the top of the scoring list. Ronaldo has 36 goals in all competitions this season.

"Ronaldo's goal changed the game for us, a fantastic header," United manager Alex Ferguson said. "I thought Roma had some good chances the first 15 minutes of the second half. But there are breaks in a football match and I think they were with us today."

Rooney added the second goal in the 66th when Roma goalkeeper Alexander Doni couldn't collect a header from Park Ji-sung. The ball landed at Rooney's feet for an easy score, his fourth in European competition this season.

"They were lucky on their scoring chances," Roma coach Luciano Spalletti said. "They have players of very high quality."

The second leg of the total-goals series is April 8 at Old Trafford, where United routed Roma 7-1 a year ago. Roma hopes injured captain Francesco Totti will return then.

"We can't take anything for granted, but we definitely feel like we can reach the semifinals," Ferguson said.

In Tuesday's other quarterfinal, 17-year-old Bojan Krkic scored in the 12th minute to give Barcelona at 1-0 victory at Germany's Schalke. Thierry Henry's shot was fumbled by goalkeeper Manuel Neuer, and Henry played the ball back across for Krkic, who tapped it in at the far post.

"We played well on the flanks. We won the ball. We controlled most of the game," Barcelona coach Frank Rijkaard said.

On Wednesday, Liverpool is at Arsenal in a matchup of English clubs and Chelsea is at Turkey's Fenerbahce.

------

AP Sports Writer Nesha Starcevic in Gelsenkirchen contributed to this report.