Everton gained their second 'top-four' scalp in two games at Goodison Park, beating Chelsea 2-0 in the Premier League on Saturday.
David Moyes' men opened the scoring just five minutes in courtesy of Steven Pienaar's wonderfully controlled strike, with the South African making his return from a loan stint at Tottenham.
The hosts then pinned Chelsea back with some brilliantly incisive attacking and got a deserved second goal through Denis Stracqualursi to follow up their recent win over Manchester City with another impressive victory.
It was a dream start for Everton, as a coming together between Tim Cahill and Frank Lampard saw the ball loop over the Blues' defence and somewhat fortuitously into the path of Pienaar, who controlled it brilliantly on his chest and smashed a strike beyond Petr Cech.
The lead was no more than the hosts deserved and they almost added a second just moments later as a Phil Neville cross was met by the head of Stracqualursi, who nodded inches wide of the post.
A Landon Donovan drive from distance, which stung the palms of Cech, gave the hosts further hope of stamping their dominance on the scoreboard, as Andre Villas-Boas' men appeared rattled.
It took 25 minutes for the Londoners to show any sort of fight but a Fernando Torres on-target header was brilliantly denied by Sylvain Distin, before Daniel Sturridge saw his shot desperately blocked at the edge of the box.
Lampard then rolled a shot wide from a similar distance to confirm Chelsea's arrival in the match just early enough for them to try and turn the tide.
A wild kick from a frustrated Raul Meireles on the breaking Stracqualursi, however, canvassed Chelsea's frustrations in the first half, yet the hosts failed to capitalise with the free-kick.
A Torres header from close range was then easily collected by Howard as an entertaining first period was brought to a close with Everton taking their advantage to the break.
The pace did not appear to have slowed as the second half commenced, with both sides continuing to show the attacking intent which had the game so good to watch.
And Everton proved why they would be deserving winners, landing the knockout blow with 15 minutes remaining on the clock.
A brilliant run in off the right from Donovan found the Blues' defence backpedalling, and the American's weighted pass allowed striker Stracqualursi to fire on target and seal a valuable three points.