That's the view of Everton manager David Moyes, a guest on Monday Night Football, who says the result will be especially significant for Baggies boss Steve Clarke on his return to Anfield.
Gareth McAuley headed the visitors into the lead in the 81st minute after goalkeeper Ben Foster had saved Steve Gerrard's penalty, before substitute Romelu Lukaku wrapped things up in time added on.
"West Brom did the job," said Moyes. "I'm sure that Steve Clarke would have been delighted with a point but I'm sure that he'll be thrilled to go away with all three.
"They rode their luck - the goalkeeper [Foster] played really well. They had to be patient because Liverpool had quite a few opportunities but West Brom stuck at it and in the end it's a great three points."
Clarke was appointed boss at West Brom in June 2012 after working as number two at Newcastle, Chelsea and Liverpool, where he assisted Kenny Dalglish.
His side went to Anfield having taken only one point from six matches - their last league win coming on Boxing Day - while Liverpool were unbeaten in three after thumping Norwich 5-0 and drawing away at Arsenal and Manchester City.
Moyes said that made West Brom's victory all the more impressive.
"You've got to remember that Steve was the assistant manager last year with Kenny and he's gone back there," said Moyes.
"He was going there to play an in-form Liverpool, his team was not playing so well; he knows that he's been struggling to find a win. So that was a big result for him.
"Their position in the league hasn't changed that much even though they've not been doing that well so they'll get a big boost from that result."
The win means that West Brom leapfrog Liverpool up into eighth place, while Brendan Rodgers' side have still yet to beat a team that is currently in the top half of the Premier League this season.
Moreover, Liverpool are now 12 points off the top four and Monday Night Football pundit Gary Neville said that given his side's recent displays, Rodgers would find the defeat particularly deflating.
"I think it's a big setback because after the last couple of weeks with the Arsenal and City away performances, he'll have recognised that West Brom at home is a difficult game but I'm sure he'd have been looking to get on the shoulder of Everton and Arsenal, and really pushing for that fifth or sixth spot.
"This is a step back. The first half was a little bit back to how they were a few weeks ago. Daniel Sturridge had given them a little bit of a new dimension - a genuine frontman alternative to Luis Suarez.
"So when Suarez goes wandering, particularly to that left channel which he likes to do and moves into that area they've still got that centre forward.
"I think they struggled with that in the first half but in the second half they pressed well - for 330 to 35 minutes they were by far the better team. West Brom sat back in.
"Liverpool got the penalty but it was saved and that gave West Brom a big lift. Liverpool then get done by the sucker-punch."