West Brom stretched their lead at the top of the Championship to seven points after a routine 2-0 win over Preston.
First-half goals from Hal Robson-Kanu and captain Jake Livermore punished some poor defending from Preston.
North End had to play the last 26 minutes with 10 men following the straight red card issued to right-back Darnell Fisher.
The Baggies moved further clear of second-placed Leeds, who play on Wednesday, while their advantage over Nottingham Forest in third is 10 points.
West Brom threatened with an early set-piece when Filip Krovinovic's curling free-kick flew a foot over the crossbar.
The hosts took the lead in their next attack in the sixth minute as Preston were caught ball watching in their own penalty area.
Callum Robinson floated a ball in from the left and after Ben Davies and Andrew Hughes failed to challenge, Robson-Kanu got between them, chested the ball down and bundled home left footed from six yards out.
It was the Wales international's 10th goal of the season, the best tally of his career.
Albion threatened again when left-back Conor Townsend advanced and saw a left-foot drive deflected behind before Krovinovic twice fired straight at goalkeeper Declan Rudd.
West Brom went close to doubling their lead in the 29th minute. Matheus Pereira split the defence to find Robinson, whose first-time shot was parried by Rudd and bounced just in front of goalline before Fisher cleared.
Preston failed to mount any threat until the 32nd minute, when David Nugent climbed above Dara O'Shea to glance just wide from Fisher's hanging cross.
After Albion goalkeeper Sam Johnstone punched away a Daniel Johnson free-kick, West Brom quickly returned to the attack.
Pereira again split the defence for Robinson, and Rudd produced more heroics to block his shot then parry Krovinovic's volley into the ground from the rebound.
Albion's second goal duly arrived in the 45th minute after more pedestrian defending. Livermore speared a left-foot volley into the far corner of the net from 15 yards after Robinson's cross from the right was chested down by Robson-Kanu.
The second half was largely uneventful until Fisher's dismissal for lunging in on Robinson in front of the dugouts.
Albion could and should have made it a more comfortable victory.
Substitute Charlie Austin's shot was tipped over by Rudd and Rekeem Harper's curling effort hit the top of the bar.
What the managers said...
West Brom's Slaven Bilic: "It was a very mature performance. We looked in control and on the front foot. People are talking about routine but we made it like that. We were playing against a team that normally has great intensity and maybe the best in the division in transition.
"We did to them what they were going to do to us - the intensity, pressing, second balls - all of that gave us a platform to catch them in transition."
Preston's Alex Neil: "At the time I wasn't quite sure, having seen it back I think it's a soft one. The fourth official said it was for the follow through with his left leg but watching it back his left leg doesn't follow through at all. It was harsh but it continued a theme of the officials all game."
"I didn't think we played particularly poorly. The biggest difference was their front four, who threatened all game. The biggest disappointment for me was probably the cheapness of the goals. For their first goal we gave the ball away on the halfway line and for the second we gave it away on the edge of our own box."