Spurs were heavy favourites against the in-form Championship side and showed their class for much of the match as Moussa Sissoko and Heung-min Son netted in each half in a largely routine win.
There was one sour note for Spurs when Pierre-Emile Hojbjerg was forced off the pitch following a horrible challenge late on, though Jose Mourinho was clearly delighted to overcome what he had dubbed beforehand as the ‘biggest game’ of his reign so far.
Although the Championship side started brightly, it was Spurs who took the lead through an unlikely source as an unmarked Sissoko expertly headed home Sergio Reguilon’s inch-perfect cross.
As has often been the case in Tottenham matches this season, the early lead saw Mourinho’s side take a step back, containing and nullifying Brentford without showing too much ambition themselves as they took control of the opening 45 minutes.
Hugo Lloris was a virtual spectator, with the only real chance of note for either side coming shortly before the break when Lucas Moura’s header looped off Ivan Toney and produced a good stop from David Raya.
Brentford started the second half brightly, with Toney forcing Serge Aurier to make a crucial block, before the Ivory Coast international very nearly scored himself up the other end but blazed over.
That scare seemed to liven Spurs up and they increased their intensity in the minutes that followed, grabbing a second goal that virtually killed off the tie with 20 minutes still left to play.
Good work down the left saw Harry Kane feed Tanguy Ndombele and the rejuvenated midfielder played a brilliant pass in behind the Brentford defence for Son, who took a couple of touches and then rifled the ball into the back of the net.
Kane had a chance to put the game beyond all doubt but was denied at close range by Raya before Ndombele then rattled the post from a very acute angle.
Brentford’s hopes then disappeared when Josh Dasilva was shown a red card by Mike Dean after an intervention from VAR, having gone studs-up over the top on Hojbjerg leaving the Dane absolutely seething and with blood trickling down his shin.
Hojbjerg did not appear to suffer a serious injury in the challenge, though was subbed off as tensions flared, and Spurs can now look forward to the later-than-usual final at Wembley on April 25 after an almost perfect evening.