Emil Riis piled the pressure on Steve Bruce as Preston extended West Brom's winless Sky Bet Championship run to seven games.
In a lively start to the game, Riis converted Alvaro Fernandez’s seventh-minute cross to get the visitors off to the perfect start.
Grady Diangana might have levelled almost immediately and Jed Wallace and Okay Yokuslu both went close before the break, and although West Brom enjoyed the better of the second half, they were unable to find a way past North End keeper Freddie Woodman as they slipped into the bottom three after a 1-0 defeat.
Alan Browne and Robbie Brady both played over an hour for Preston, while Troy Parrott got the last five minutes, while the Baggies were captained by Dara O'Shea and gave Jason Molumby an hour.
Ben Cabango struck eight minutes into stoppage time as Swansea came from behind to win 2-1 at Watford.
Cabango made the decisive intervention on a night when a problem with the officials’ communications system saw 17 minutes of added time signalled and 21 played at the end of the game.
Ismaila Sarr’s 34th-minute goal handed the Hornets the advantage at the break, but the Swans were level within seven minutes of the restart thanks to Olivier Ntcham, and Cabango took full advantage when he got his head to Republic of Ireland international Ryan Manning’s late cross.
Michael Obafemi also played the full game for the Swans.
Oscar Estupinan’s first goal in six games handed managerless Hull a comeback victory over Wigan.
Will Keane gave the Latics the lead at the MKM Stadium, but it wasn't enough as they lost 2-1. James McClean played the full game, while Cyrus Christie did the same for the hosts.
Chuba Akpom’s first-half strike ensured caretaker Middlesbrough boss Leo Percovich’s big night ended with a 1-0 victory over Birmingham.
Akpom fired the Teessiders, who parted company with Chris Wilder on Monday, into a 23rd-minute lead when he stabbed home from a corner, and they saw out the game to claim their first win in four.
Darragh Lenihan played the last 20 minutes for Boro, while Scott Hogan played the full game for the Blues but couldn't find the back of the net at the Riverside Stadium.
Harry Clarke’s last-gasp header denied promotion-chasing Burnley victory as Stoke bounced back from their weekend nightmare to claim a creditable point.
Substitute Clarke converted Tariqe Fosu’s 87th-minute cross to snatch a 1-1 draw at Turf Moor three days after the Potters’ 4-0 home drubbing by Watford.
Connor Roberts had scored for the home side nine minutes into the second half, but Vincent Kompany’s men saw two points slip from their grasp.
Josh Cullen played the full game for the hosts, while U-21 international Will Smallbone did the same for the visitors.
Rotherham and Millwall had to make do with a point apiece as their clash at the New York Stadium ended 1-1.
Dan Barlaser put the Millers ahead with a ninth-minute penalty after Jake Cooper had fouled Ben Wiles, but the visitors were back in it three minutes before the break when Zian Flemming smashed a shot into the top corner.
Chiedozie Ogbene played the full game for The Millers.
Additional reporting: PA
