Barcelona closed in on a likely Champions League semifinal with Spanish rival Real Madrid by routing Shakhtar Donetsk 5-1, while Wayne Rooney's goal gave Manchester United a 1-0 win at Chelsea in yesterday's other quarterfinal match.
Goals by Andres Iniesta, Dani Alves, Gerard Pique, Seydou Keita and Xavi Hernandez in the first leg put Barcelona on the brink of qualification, with Yaroslav Rakitskiy scoring an away goal at Camp Nou stadium for the Ukrainian underdog.
Chelsea was looking to gain revenge for a penalty shootout defeat to United in the 2008 final in Moscow, but a superb team goal converted by Rooney in the 24th minute put Alex Ferguson's side in the driving seat ahead of Tuesday's second leg
"We have an advantage now but the biggest advantage is going back to Old Trafford," Ferguson said. "But it's only one goal. We will need a good performance on Tuesday."
After high-scoring matches in Tuesday's quarterfinals, with Real Madrid thrashing Tottenham 4-0 and Schalke upsetting defending champion Inter Milan 5-2, Barcelona carried on the theme to show why the team is most people's favorite to win the competition for a fourth time.
Iniesta scored in the second minute, running onto Lionel Messi's blocked pass and slotting a finish into the corner, before setting up right back Dani Alves to make it 2-0 in the 34th.
Shakhtar had chances before halftime, with Willian's close-range shot being tipped over and Luiz Adriano sidefooting wide when clean through.
But the visitors always looked likely to concede at the other end and Barcelona's third goal from Pique, which took a deflection off Rakitskiy, sealed the win.
Rakitskiy made amends by connecting with a free kick using his knee to turn the ball past Victor Valdes for what looked at the time like a precious away goal, but late goals from Keita and Xavi have surely given the hosts an unassailable lead.
If Madrid and Barcelona do go through as expected, they would meet four times over the next month as they also play in the Spanish league and the Copa del Rey final.
United manager Alex Ferguson said on the eve of the match that scoring an away goal would be the key to the first leg, and Rooney obliged with a wonderful strike.
Michael Carrick's raking diagonal pass was taken superbly by Ryan Giggs, who glided past Jose Bosingwa thanks to a sublime first touch and cut the ball back for Rooney to slot in off the far post from 10 meters.
Charged by England's Football Association for swearing into a television camera while angrily celebrating a league goal on Saturday, Rooney's face four days later was a picture of happiness as he was mobbed by his teammates in front of Chelsea's fans to celebrate his 13th United goal of the season.
"Wayne got a lot of abuse and late tackles but he played his game," Ferguson said. "He was important on the counterattack and he was in tremendous form and he has given us a great chance of reaching the semi."
Up to the goal, Chelsea had edged proceedings but lacked a killer touch, with Fernando Torres and Didier Drogba again failing to gel up front. United also looked the more composed, especially in midfield where the evergreen Giggs showed his class.
The hosts came close to equalizing in first-half injury time when Drogba's cross was missed by Torres and ended up hitting the post. Frank Lampard, making his 500th appearance for Chelsea, pounced on the rebound but his shot was cleared off the line by Patrice Evra.
Chelsea threatened to equalize in the second half, with Torres' header in the 74th forcing a fine save out of Edwin van der Sar and Michael Essien also going close.
Referee Alberto Undiano Mallenco then refused Chelsea what looked like a clear penalty in second-half stoppage time, when Evra got away with chopping down Ramires just inside the area.