Preston opened the scoring after six minutes when ex-Baggies player Darren Carter, a signing in the summer in a deal worth £1.25million, hit a left-foot right-wing corner over and Preston French centre-back Youl Mawene put a bullet header from inside the six-yard box into the keeper's top left-hand corner of the net for his third goal of the season.
Carter had a speculative drive which went high over the bar after nine minutes and West Brom captain Jonathan Greening fluffed a great chance in the penalty box moments later.
Chris Brown saw a 25-yard right-foot shot fly over the bar and it was Brown again with a run into the box on the right-hand side before a right-foot cross missed Karl Hawley, but fell to Simon Whaley who shot against the keeper's right-hand post after 35 minutes.
Felipe Teixeira had a shot from the edge of the box saved by Preston keeper Andy Lonergan for a left-wing corner and Teixeira again had another shot saved and followed up with a rebound which was disallowed for handball.
Man-of-the-match Lonergan made another great save from Roman Bednar just before half-time from close range and saved again after a big scramble in the box which led to the ball being cleared.
Zoltan Gera had a 25-yard shot saved, but in the 50th minute he picked up a loose ball and hit a 25-yard right-foot screamer into the keeper's top right-hand corner of the net to make it 1-1.
James Morrison broke through beating Callum Davidson before having a close-range shot saved by Lonergan.
Karl Hawley made it 2-1 to Preston with a close-range header from a Paul McKenna left-wing free kick after 72 minutes.
Mawene and Bednar were booked for an altercation and Gera had a shot touched on to the bar by Lonergan as time ticked away.
Mawene then saw red when he wouldn't leave the pitch with blood on his shirt and Brown was given a yellow card for a foul in the 89th minute and then a red card for another foul in the final minute.