CHELSEA'S love affair with the FA Cup and the new Wembley inspired them again as a superb Demba Ba goal ensured the famous old trophy remains in their sights.
Instead of a Manchester derby semi-final, it is the Blues who will take on Man City on April 14 for a place in the final.
Ba's goal four minutes after the interval was worthy of the big occasion, as was a sensational world-class save from petr Cech that followed 12 minutes later.
Ba darted in behind Rio Ferdinand onto one of those perfect Juan Mata chips that can bisect the best of defences, but the striker had to demonstrate perfect technique to send a controlled volley across David De Gea as the ball dropped over his right shoulder.
Blues fans had barely drawn breath after the celebrations when they were left awestruck by another moment of brilliance at the other end of the field to preserve their lead.
A cross from the right by Danny Welbeck looked for all the world as though it must be a goal when Javier Hernandez met the ball well with a header from six yards. Yet somehow, Cech kept it out – flicking up his left hand instinctively to turn the ball over the bar. It was a breathtaking stop.
It was one of those great FA Cup goalkeeping moments. Think Jim Montgomery for Sunderland in the 73 final, or David Seaman against Sheffiekld United in an Old Trafford semi-final.
After those two outstanding moments, the tempo kept rising and chances followed.
Eden Hazard latched onto a stray Michael Carrick pass to almost establish a two-goal cushion – his left foot shot flashing just wide – while Mata hit the side-netting.
Manchester United did not have an unfit Wayne Rooney and Alex Ferguson's decision to keep Robin Van Persie on the bench for an hour did not pay off, although the ex Arsenal striker might have tied it up when he had a free volley from eight yards that he put well over the bar – Patrice Evra having created the opening down the left.
That heart-in-mouth moment was as close as United came to spoiling the occasion and it was Chelsea who looked more likely to score on the counter-attack – the visitors not looking at their best and surely regretful that they surrendered a 2-0 lead in Manchester and were taken to this unwanted replay.
Both teams were playing their second game in 48 hours, but undoubtedly it was Chelsea who showed the greater appetite and they were well worth their win.
Given the glut of goals the teams served up in three previous meetings this season – 18 in all – the first half was a disappointment.
The departure of Ashley Cole midway through the half with a hamstring strain was the only noteworthy incident until Hazard slipped Ba in for an angled drive inside the area that De Gea saved with an outstretched left leg.
Hazard flashed an effort over the bar after an exchange of passes with Oscar on the edge of the area, while Nani's 30-yarder arrowed just wide and Hernandez's swerving effort almost deceived Cech, who only just got a leg to the goalbound shot.
But whatever the first half lacked, the second half made up for it - certainly from a Chelsea point of view.
Line-up: Cech; Azpilicueta, Ivanovic, David Luiz, Cole (Bertrand 22); Ramires, Mikel; Oscar (Moses 90), Mata, Hazard; Ba (Torres 90). Subs not used: Turnbull, Lampard, Benayoun, Terry.