Goals by Didier Drogba and Juan Mata either side of halftime put Chelsea in command before Gareth Bale replied for Spurs but Ramires, Frank Lampard and Florent Malouda struck again for the Blues who will meet Liverpool in the final next month.
Mata’s goal in the 49th minute proved a major turning point as his shot appeared to have been blocked before crossing the line only for referee Martin Atkinson to award the goal.
In the end the decision did not prove decisive as Chelsea ran out easy winners to give themselves a boost before hosting Barcelona in the Champions League semi-finals on Wednesday.
The one worry for Chelsea was an injury to central defender David Luiz who went off on a stretcher in the second half.
Chelsea, winners of the FA Cup in 2009 and 2010, took the lead against the run of play in the 43rd minute when Drogba controlled Lampard’s lofted pass, held off William Gallas and thrashed an unstoppable shot past Carlo Cudicini, one of three former Chelsea players wearing Spurs shirts.
Before that Tottenham had twice gone close to taking the lead, once when John Terry blocked Rafael Van der Vaart’s goalbound header on the line and then when Van der Vaart’s swinging pass evaded Spurs striker Emmanuel Adebayor and Chelsea keeper Petr Cech but bounced off the post.
Tottenham began the second half groggily and Mata could have made it 2-0 with a low shot brilliantly saved by Cudicini.
Chelsea did not have to wait long to double their lead.
Cudicini again made a great save to deny Drogba and when the ball broke to Mata he fired goalwards. The ball appeared to be blocked by the keeper and Terry who was prone on the turf.
To the astonishment of Cudicini, the Spurs players and even Terry, the referee Martin Atkinson awarded the goal.
“I thought Mata’s strike hit me and didn’t go over, but the linesman’s seen it and given it,” Terry said.
“I honestly don’t think it went over the line but the linesman gave it and there’s nothing we can do about that.
“Spurs are one of the best sides in the league. It was a great performance and a great result.”
Tottenham’s goal also had a tinge of controversy.
Scott Parker put Adebayor through on goal and when he pushed the ball past Cech he was sent tumbling by the keeper. However, Cech escaped any punishment as Bale followed up to score into an empty net.
Tottenham pressed forward but were dealt another blow after 77 minutes when Ramires got behind Benoit Assou-Ekotto and finished coolly past Cudicini.
Lampard’s long-range free kick past Cudicini sent Spurs fans streaming for the exits and Malouda completed the party for Chelsea with a tap-in fifth.
With a Cup final booked on May 5, Chelsea now face a massive week as they take on Barcelona in the first leg of their Champions League semi-final before a Premier League clash with Arsenal next weekend.
For Tottenham, a season that offered so much promise is crumbling before their eyes and they are left with the sole aim of trying to secure a top-four finish in the league.
