Ben Watson's first-half header had drawn Palace level on aggregate following City's 2-1 win on Saturday, but the Eagles midfielder turned from hero to villain when he missed a penalty with 18 minutes remaining.

That forced extra time but Lee Trundle's left-footed curling effort in the 104th minute and Michael McIndoe's drilled free-kick five minutes later ensured Gary Johnson's side will face either Hull or Watford at Wembley on May 24 for a place in the Premier League.

It was a first play-off semi-final defeat in six attempts for Palace boss Neil Warnock but he could have few complaints over City progressing.

They almost began the game the way they finished the last when Marvin Elliott came close with less than two minutes gone.

A cross from the man who scored the first leg's 90th-minute winner, David Noble, was punched straight to Elliott by Palace goalkeeper Julian Speroni only for Mark Hudson to clear the midfielder's goal-bound header off the line for a corner.

The Eagles had a shout for a penalty when Scott Sinclair went down in the area as he tried to find a way past Jamie McCombe and Louis Carey, however the claims were waved away by referee Howard Webb.

But soon the visitors had their lead.

It was a moment to forget for Robins defender McCombe, who should have left Danny Butterfield's floated cross for goalkeeper Adrian Basso but instead gave the ball straight to Watson.

The Eagles midfielder, who also scored for Palace in the first leg, took full advantage, guiding his looping header into the empty net from the edge of the area.

To compound the defender's misery he lost a contact lens during the incident and was forced to retreat to the dressing room for a new one.

However, he almost made amends with a close-range header six minutes before half-time.

Hill was booked for an over-zealous challenge on Carey shortly before the whistle which sparked angry words on the field and the sidelines, setting the game up for a fiercely-contested second half.

City could count themselves unfortunate to be behind on the night, but it was only an excellent Speroni save from Elliott which prevented them reclaiming the initiative.

The match moved at a furious pace with City threatening down the wings and Palace responding on the counter - one last-ditch block from Carey timed to perfection to deny Scannell.

Dele Adebola should have pulled the trigger earlier after losing his marker midway through the second half and the Palace rearguard had time to recover.

The pendulum appeared to swing firmly in Palace's favour when Nick Carle mistimed a challenge on Soares - only for Watson to fire his spot kick against the foot of the keeper's right-hand post, prompting the majority of Ashton Gate to erupt.

Inevitably, both sides began to run out of steam as the prospect of extra time loomed large, but each came within inches of snatching victory at the death.

First, Scannell's deflected effort looped agonisingly on to the roof of the net and, down at the other end, Trundle came even closer with a delightful lob which clipped the top of the crossbar.

The former Swansea striker then went one better with a minute of the first half of extra time remaining, curling a stunning effort beyond Speroni.

Adebola should have sealed it early on in the second period but the Robins made sure when Carle laid the ball off for McIndoe to fire a low shot inside the left post.

The result prompted a mass pitch invasion at the final whistle as Johnson's men moved within one game of ending their 28-year exile from the top flight.