Jerry Yates (left) has now scored five goals in 20 Championship appearances this season
Jerry Yates was on target for a spirited Derby County as they ensured promotion-chasing West Bromwich Albion began life without Carlos Corberan with defeat at Pride Park.
Yates fired in the opener from a tight angle early on as the Rams capitalised on a slow start by a Baggies side under the caretaker charge of Chris Brunt, Damia Abella and Boaz Myhill.
West Brom, who would have gone into the play-off spots with a victory, struggled to find their fluency but hit the post twice before the break, first with a rasping low strike by Darnell Furlong and then with a classy John Swift free-kick.
And although the pressure started to mount in the second half, Derby stood firm and doubled their lead when Kayden Jackson's well-struck shot from the right deflected into the net off Albion defender Mason Holgate.
Substitute Grady Diangana's far-post header from an exquisite Tom Fellows cross with 10 minutes remaining brought the visitors hope of a comeback
However, Derby saw out a second win in three Championship matches to move up to 14th in the table and leave West Brom - managerless following Corberan's departure for Valencia - in eighth place.
Diangana's first goal of the season left a raucous home support fearing late drama akin to the game against Luton Town, which saw Derby lead 1-0 in the 89th minute, only to lose 2-1.
Rams keeper Jacob Widell Zetterstrom did have to make a fine block with his legs from Karlan Grant and the hosts also survived an almighty injury-time goalmouth scramble in which Sonny Bradley made a brilliant block.
Albion will point to twice hitting the post, having more than 60% possession, and an increasingly strong finish.
But their first attempt on target did not arrive until more than an hour had been played, when Alex Mowatt's curling strike from distance was palmed away by Widell Zetterstrom.
The second home goal revitalised Derby for the closing stages and they defended impressively to secure a seventh league win of the season.
'We gave ourselves too much to do' - reaction
Derby hoss Paul Warne told BBC Radio Derby:
"I'm really pleased. We started really well but we didn't take one of our chances. But Jerry scored a good goal and we had pretty good control.
"Apart from the two strikes that hit the post, they didn't really lay a glove on us.
"The second goal was a bit fortuitous but we put our bodies on the line and did enough to see out the game.
"We have always been really competitive in the Championship. Since the Leeds game we should have had 10 points from four games but we threw away points against Luton.
"Today we possibly had some luck that we haven't had before."
West Bromwich Albion co-caretaker boss Chris Brunt:
"In the end we gave ourselves too much to do. We knew what was coming and didn't deal with it well.
"Individual errors are a part of game and we won't have a go at anyone trying to do the right thing. This is a tough place to come.
"I had a phone call late afternoon Christmas Eve saying that there is a possibility. Then another one saying it's happening, we could do with your help.
"Why would you change what's gone pretty well for the majority of the season? We've been in every game, so why change that? Carlos prepped a lot before he left.
"Carlos did a great job here for two years and left us in a better place than when he came in, and you can't say that often. He's not left us in a bad place and what he achieved last year, getting us to the play-offs."
