Osaze Odemwingie celebrates after ending his six-match goals drought
West Brom recorded their first win at Anfield since 1967 as Liverpool were made to pay for their extraordinary wastefulness in front of goal, on a day that Manchester City closed the gap on their rivals, United to just three points with their victory over Wolves, which consigned them to relegation.
The Reds laid siege to the Albion goal throughout, with Jordan Henderson striking the underside of the bar and Dirk Kuyt the inside of the post.
But they were stunned on the break when Glen Johnson's error let in Osaze Odemwingie to fire past Pepe Reina. It was the Nigerian international’s first goal in six games and 10th of the season for the Baggies.
Liverpool have now won only five of their 17 home league games this season.
Meanwhile, goals from Sergio Aguero and Samir Nasri saw Manchester City relegate Wolves and move to within three points of leaders Manchester United.
Both sides had early chances before City took control and Aguero slid them ahead from Gael Clichy's superb cross.
Joe Hart made an excellent save to deny Steven Fletcher as Wolves worked hard to level, but Nasri slotted in to earn his side a vital win in the title race.
If City beat United at home on 30 April they will be top with two games left.
Their goal difference is six superior to that of their local rivals and all eyes will now be on that meeting at Etihad Stadium.
City spent much of the season in top spot but their defeat at Arsenal on April 8 left them eight points behind United with six games remaining.
Suddenly, though, they are very much back in contention and it promises to be a thrilling end to the campaign.
The same can not be said for Wolves, who drop into the Championship after three years in the top flight.