Goals: Dawson 87′; Salah 57′, 68′, Wijnaldum 84′
The Premier League champions faced their second tough away game in London in less than 72 hours, following their 3-1 victory at Tottenham on Thursday night.
A low-key first half unfolded at the London Stadium, with chances few and far between and Liverpool missing Sadio Mane and Roberto Firmino.
After the break, the Reds turned on the style, though, with Salah scoring two wonderful goals in their own right – one a solo effort and the other a devastating counter-attack.
Gini Wijnaldum added a third late on and Craig Dawson scored a consolation for the Hammers, as Liverpool picked up a huge three points.