This ended up feeling like a thrashing, the massed ranks of Chelsea support crowing in giddy celebration as bitter rivals were mercilessly tormented and, ultimately, torn apart. Yet, while Roberto Di Matteo's side will now thrill at the prospect of a fourth FA Cup final in six years against Liverpool next month, Tottenham Hotspur departed this competition crying injustice.

As Chelsea's recently traumatic season suddenly gathers pace on three fronts, so Spurs' once consistent campaign is unravelling disconcertingly. Their endeavours here were horribly undermined by the award of Juan Mata's goal after half-time despite the reality that the Spaniard's effort had been scrambled from well in front of the goal-line by Benoît Assou-Ekotto.

Almost a year ago Heurelho Gomes had appeared to deny Frank Lampard similar reward on the line when these sides met at Stamford Bridge, only for the officials to rule against the Brazilian. The surroundings may be different but Tottenham's luck is still out.

The final scoreline hints at the latest incident not having been critical. Spurs, after all, were already behind by then and went on to muster a reply of their own within seven minutes through Gareth Bale. Yet derbies such as this owe so much to momentum and Chelsea's second goalhad changed the complexion of the contest, reducing Tottenham to a game of catch-up. Their form has been so brittle of late, with only one win in eight Premier League games, that it was less of a surprise that they were cut to shreds when chasing the match late on.

By the end, with Scott Parker incensed by John Mikel Obi's petulant kick, it was easy to forget that Chelsea had not been the slicker of these sides for long periods. They were, however, always the more ruthless.

The vanquished will cling to the controversy as their undoing. Mata had been denied by Carlo Cudicini when, from the resultant corner, David Luiz's near-post header was saved well by the Italian. John Terry and Ledley King leapt to meet the rebound with the ball squirting away for Mata to volley from a tight angle into the mass of bodies in the goal-mouth. Assou-Ekotto, grounded behind the line, stuck out his boot as the ball flicked from King and Terry to clear, only for Martin Atkinson to award the goal.

The same official had failed to notice Mario Balotelli's lunge high into Alex Song's shin at the Emirates a week earlier but was convinced here despite his linesman being unmoved and Mata the only Chelsea player to celebrate. Terry, who had been lying in a tangle with King, later admitted the ball had hit him "and stayed out". He had been part of the England side denied back in Bloemfontein against Germany but, while testing is on-going, nothing will happen until Fifa and the International Football Association Board finally give the go-ahead on 2 July in Kiev. Spurs will merely grimace at the irony that Atkinson will spend his summer as a goalline assistant at Euro 2012.

A sense of injustice did propel them into an immediate riposte, Parker conjuring a fine through-ball between Terry and David Luiz on to which Emmanuel Adebayor tore. The Brazilian pulled up and was prone on the turf - he departed on a stretcher, his hamstring damaged, to render him unlikely to feature against Barcelona - as Cech advanced to clatter into Adebayor, though not before the Togolese forward had slipped a pass to the galloping Bale at his side. The winger converted into the unguarded net with the Tottenham bench already advancing on the fourth official to demand Cech's dismissal for a professional foul. "I'd rather have had the penalty and a sending-off than the goal," admitted Harry Redknapp.

Yet, if that suggested Redknapp's team were still in contention, the adrenaline rush soon fizzled out. Chelsea waltzed through their disrupted back-line at will in the latter stages, so stretched and desperate had Spurs become. Ramires, finishing smartly from Mata's pass, re-established a two-goal cushion and Frank Lampard fizzed in a glorious free-kick from 30 yards which swerved beyond Cudicini. Tottenham were helpless and Florent Malouda's fifth was scored in stoppage time with the Tottenham end rapidly emptying.

Chelsea have rarely been this clinical this season. The Di Matteo effect has been remarkable - his record is now nine wins in 12 games - and confidence will have been pepped ahead of the Catalans' visit. It felt odd to acknowledge that their lead had felt improbable at the interval.

Spurs had struck a post through Rafael van der Vaart and had exposed their opponents down both flanks, only to be nullified by a lack of bite. Terry cleared Rafael van der Vaart's header from the goalline and, from a mess of a personal performance, Didier Drogba duly stirred. Marked tightly by William Gallas, the Ivorian received on his chest with his back to goal, delicately flicked the ball out of his feet with the instep, the turned and crunched a volley that flew high beyond Cudicini at his near post. The 34-year-old has scored seven goals in this arena, more than he has managed at any other stadium other than Stamford Bridge. Spurs will remember this occasion for the one that should never have been.