A Carling Cup semi-final now awaits after the team came from a goal behind to defeat Watford at Vicarage Road on Wednesday night.
The early setback was overcome moments before half-time when Roman Pavlyuchenko converted a penalty, with Darren Bent booking our last four place with 15 minutes remaining.
It was frantic stuff from the off with the home side certainly speedier out of the blocks and probably quicker in warming up on a cold night in Hertfordshire.
Fraizer Campbell attempted to slice open what, early on, looked like a resolute Watford rearguard with a slide pass roughly into the path of Didier Zokora, but his assist-attempt was overhit and Zokora's wait for a goal was always going to extend.
With 12 minutes on the clock Tommy Smith's determined dash down the left led to the ball being squeezed inside to Tamas Priskin. The striker still had a fair bit to do, but did it in a clinical fashion, turning in the area and powering a low curling shot beyond the reach of Heurelho Gomes and into the net.
Twenty minutes in Zokora set Aaron Lennon on the run and, after checking inside his marker, the winger employed the outside of his boot and sent the ball swirling towards the top corner. Home goalkeeper Scott Loach was forced into a magnificent save on the stretch.
Territory, possession and a genuine threat going forward began to be posed, the feeling being that if the final ball was right then the pace of Lennon or Campbell could well pay dividends.
However, it was Gomes making the next save with a smart smothering of Liam Bridcutt's low drive, before Loach did similar at the other end. Loach was slightly less assured in dealing with the threat when Lennon burst through, pushing up in the air leaving Campbell to attempt to nudge home, but the danger was finally averted.
Two minutes before the break Pavlyuchenko had the chance to square the game when he seized on an error by Leigh Bromby and stole in on goal. The Russian went for the top corner and hit the bar with only the keeper to beat.
In stoppage time Jermaine Jenas was tagged by Ross Jenkins inside the area and, after taking a good look, referee Mr Dowd pointed to the spot. Pavlyuchenko did the honours and it was evens at the break.
Watford began the second half with renewed purpose without unduly troubling Gomes, while we laboured to recapture some of the vigour from the latter stages of the first half.
Bent was summoned from the bench not long after the hour in place of Campbell in a bid to sharpen up the attacking intent, but it was Zokora who sped the length of the pitch on the counter before delivering a disappointing cross that Loach was able to field with ease - as he did two low efforts from Jenas and one from O'Hara.
Pavlyuchenko came close to unlocking the gate when he spread the play wide to Benoit Assou-Ekotto, who pinged the ball across the face of goal awaiting a touch that never came. A Jonathan Woodgate header, albeit not the most powerful, was nodded off the line by Lee Williamson.
In the 76th minute the deficit was finally overturned when Lennon combined with Pavlyuchenko before the ball sprang off Bridcott in the direction of Bent to the right of the penalty area. From an angle the striker aimed towards the near post, beating Loach low to his left, before joining in the celebrations with the travelling masses.
Bent could have added to his night's work three minutes from time when he attempted to seize on a Lennon cross, but was unable to make a suitable connection.
Manchester United, Derby or Burnley will be next in this competition - a two-legged semi-fial - with our opponents to be determined on Saturday.