West Bromwich Albion have booked their place in the fifth round of the FA Cup courtesy of a penalty shootout victory over Peterborough United at London Road this evening.

Darren Fletcher's strike cancelled out a Jon Taylor opener to force the shootout, and it was the Premier League outfit who held their nerve to send their spirited League One hosts crashing out.

It was the home side who made the brighter start to proceedings, and it took a flying last-ditch block from James McClean to deny Harry Beautyman inside the opening 10 minutes.

Taylor and Andrew Fox both had long-range efforts shortly afterwards too, with Ben Foster being called into action for the first time on the latter strike when he shovelled the dipping ball wide of the target.

The hosts continued to dominate possession and again came close to reflecting that on the scoreboard after 20 minutes when Beautyman was thwarted by Foster from inside the area having allowed the ball to run across his body.

West Brom finally began to settle into the game as the first half wore on, and they came close for the first time with just under 10 minutes remaining until the interval when Saido Berahino steered a 20-yard strike narrowly wide of the target.

A number of chances followed in quick succession for the visitors, with Jack Baldwin throwing himself in the way of McClean's strike and James Chester scuffing his finish from the resulting corner after the ball had dropped to him unmarked at the back post.

Jonas Olsson threatened from a set piece himself a couple of minutes later but got too much on his header, while Berahino had another sight of goal before the break when he curled his effort wide of the far post.

Despite the Baggies' improvement in the closing stages of the first half, it was Peterborough who came out of the blocks quickest in the second, with Taylor's free kick drawing a comfortable stop from Foster and Shaquile Coulthirst curling an effort wide.

This time they were able to turn their dominance into a goal, however, taking the lead 10 minutes after the restart when Lee Angol worked the ball out to Taylor, who was afforded too much space to send a deflected effort past a sprawling Foster and into the corner.

It began to look increasingly like it would take something special for West Brom to get back into the match and, after Craig Gardner had a go at providing it with a first-time volley that floated a few yards wide, Fletcher did come up with the moment of quality needed.

The ball dropped to the West Brom skipper on the edge of the penalty area after McClean had attacked down the left, and the Scotland international lashed a fierce first-time half-volley into the roof of the net to level things up with his side's first shot on target of the night.

Despite the setback, Peterborough continued to push for a winning goal, with Beautyman and Coulthirst both drawing saves from Foster, but it was the visitors who came closest to stealing it late on.

Ben Alnwick was forced off his line to beat Salomon Rondon to a long ball over the top, but he could only clear the ball as far as Berahino, whose subsequent effort was cleared off the line by Michael Bostwick.

Alnwick was needed to make one last save in stoppage time of the 90 to deny Rondon, but neither side could find a second goal in the closing stages as the match went into extra time.

Martin Samuelsen was the first to threaten in the added 30 minutes when he tiptoed his way to the edge of the box before firing over, and at the other end Rondon drove a low shot narrowly wide on the turn after taking the ball down 25 yards from goal.

Marcus Maddison looked to win the match in audacious style in the second period of extra time, driving forward down the right before attempting to chip Foster while in full flow, but the ball landed on the roof of the net.

The match continued to flow from end to end, and the hosts needed another goalline clearance to stay in the contest when Gabriel Zakuani, battling through on his first start since October, was in the right place to deny Gardner's well-struck volley.

There was time for one last chance for the visitors too when Gardner's late free kick found Berahino unmarked at the back post, but the striker failed to steer his header on target from close range with the fifth round at his mercy.

The miss would ultimately not cost his side a place in the last 16, however, as they went on to win the shootout 4-3 despite Fletcher dragging his spot kick wide of the target.

Foster proved to be the hero in the end, saving from Samuelsen before also keeping out the decisive effort from Angol to set up a fifth-round meeting with Reading at the Madejski Stadium on February 20.