London: With Barcelona, Real Madrid and Schalke holding emphatic leads, Manchester United and Chelsea are likely to provide all the drama in the Champions League quarterfinals this week.

Chelsea heads to Premier League rival United just 1-0 down after the first leg, while Barcelona leads Shakhtar Donetsk 5-1, Real Madrid goes to Tottenham 4-0 up and Schalke has a 5-2 advantage over titleholder Inter Milan.

So while three European rivals delve into the history books to seek inspiration before trying to pull off near-unthinkable comebacks, Chelsea sees no reason it can't oust United on Tuesday.

After all, Chelsea won 2-1 at Old Trafford last April on the way to winning the Premier League. A repeat result would take the London club through to the semifinals on away goals.

And a victory is vital, with United on course to snatch the Premier League trophy away from Carlo Ancelotti's side.

"Everyone knows we are playing to save our season," Chelsea midfielder Yossi Benayoun told the British media. "From here, it's most likely we'll finish in the top three or four and be in the Champions League next season — that's almost done. The only thing left is to try to win a trophy and the only trophy we can win is the Champions League.

"Everyone knows it's the most important game of the season. I'm sure that if we beat United, we will go to the end and win the trophy."

All the pressure, though, will be on Fernando Torres, who has failed to score since making his Chelsea debut in February.

"He is the best striker in the world," Benayoun said. "For any midfielder, it is easy to play with him and I think he will score a lot of goals."

United has never lost a two-legged Champions League fixture after winning the away match first. And striker Wayne Rooney will be raring to go after starting his two-match domestic suspension on Saturday against Fulham for swearing into a TV camera.

Manager Alex Ferguson expects the sense of injustice to "spur on" Rooney.

"There's the bonus for us of knowing he will be fit and fresh," Ferguson said. "I want us to make it clear that we can rise above recent problems and that we are a club who can overcome all attempts to knock us off our perch. This is the fighting spirit that makes Manchester United such a great club."

Meanwhile, the stunning run by Premier League rival Tottenham in its debut Champions League campaign is set to end after a 4-0 thumping in Madrid last week.

The nine-time European champions are already preparing for a triple showdown with Spanish rival Barcelona. The sides are on course to meet in the Champions League semifinals and both have advanced to the Copa del Ray final on April 20. They also meet in the Spanish league on April 16, although Barcelona currently has an eight-point lead over Madrid.

"Madrid can defeat Barcelona, they are not unbeatable," Real playmaker Kaka said. "We have to believe we can win La Liga, the Copa and the Champions League, but first we need to focus on Tottenham."

Kaka scored twice in Madrid's 3-0 victory over Athletic Bilbao on Saturday in his first start since February after struggling with injuries.

"Those two goals are good for my self-confidence," Kaka said. "I need to work hard to enjoy football again. The only problem was with my knee, which limited me from playing all out. ... I feel like I owe it to Real Madrid and the fact that I haven't fulfilled expectations bothers me."

Barcelona's players are trying to avoid appearing complacent as they head to Ukraine with a four-goal cushion.

"In football, just about anything can happen," midfielder Andres Iniesta said. "Shakhtar are very talented, particularly from their creative midfielders through to their strikers. They are dangerous and they showed their skill on the counterattack."

Shakhtar remains unbeaten at home in the last two years and will look to restore some pride after the Camp Nou rout.

"We need to pick ourselves up and show our character," captain Dario Srna said.

Schalke seems to be enjoying a new lease of life since coach Felix Magath's departure last month and will face Man United in the semifinals after winning 5-2 at Inter.

"It's fairly difficult to believe in this comeback, but anything is possible in football, even dreams are possible," Inter striker Samuel Eto'o said. "Inter is a squad made to play a great match and advance."