Peterborough Utd 0 West Bromwich 3: Phillips is spot onwhile Posh fire blanks

Tony Mowbray, tongue-in-cheek, had predicted a goalless draw between the two most free-scoring teams in the country. But by the finish, London Road had become Easy Street and West Bromwich progressed into the fifth round for the second season running.

The Championship leaders have only one ambition this season, promotion to the Premier League, but a nice little cup run is always handy. Two ahead by the interval, the manager Mowbray was able to introduce Kevin Phillips at the break and his emphatic penalty ended the contest before the hour mark.

Peterborough also had Craig Morgan sent off for felling Jonathan Greening to concede the spot-kick. "It was a bit of an anti-climax and I felt sorry for the fans," said their manager, Darren Ferguson. "We started quite well but were defending too deeply and lost to a good team. I hope they get promoted, they are the best we have seen here."

The Baggies took their goals tally in all competitions to 71 when Roman Bednar opened the scoring after eight minutes. Filipe Teixeira played in Craig Beattie and his miss-hit shot was tapped in at the far post by Bednar.

Ferguson stood, arms folded, in the technical area and within 15 minutes his side had fallen further behind. Joe Lewis tipped James Morrison's shot against the post, Beattie fluffed the rebound but this time Robert Koren was able to nudge the ball home.

Lewis's save from Beattie prevented a third before the Posh finally stirred and were unfortunate not to be awarded a penalty when Bostjan Cesar handled a header from Craig Mackail-Smith. The hosts were furious and there was further frustration when Charlie Lee's shot was tipped over by Dean Kiely and Morrison headed Morgan's effort offthe line.

Ferguson is not known to mimic his father, Sir Alex's half-time rants yet his team did come out with a spring in their step and soon Kiely was forced into a save from Aaron Mclean. But it was the Baggies who extended their lead when Beattie played in Greening, who tried to keep his feet under Morgan's challenge but to no avail. Off went the centre-back, and up stepped Phillips for his 17th goal of the season.

Mowbray said: "We came out of the blocks fast but we needed the third goal," said Mowbray.