The Hammers gave it a real go against the Reds but a goal in each half gives the visitors the points
West Ham United 0 Liverpool 2
Had it been a boxing match at Bethnal Green's York Hall, a contest between world champions Liverpool versus wobbling West Ham United would not have been allowed to go ahead.
But three miles down the road on the London Stadium turf, the uninhibited Hammers put in a plucky, pleasing performance that despite ending in a two-goal defeat left the East End with plenty of hope that there could certainly be some shoots of recovery about to emerge down West Ham way.
At half-time, only Mohamed Salah's 35th minute penalty separated a Liverpool team that is now unbeaten in 41 matches - and 19 points clear at the top of the table - from David Moyes' team, who sit precariously in 17th-spot, outside the drop zone on goal difference.
And although Alex Oxlade-Chamberlain doubled the advantage for the champions-elect early in the second-half, West Ham could take heart from a battling performance in which Declan Rice was denied by two classy stops from the world's second most expensive goalkeeper, Alisson.
Following their forlorn FA Cup exit at the hands of second-tier West Bromwich Albion, who had made eight changes for Saturday's visit to Moyes' strugglers, the Hammers boss now made half-dozen switches as the runaway Premier League leaders arrived in town.
?ukasz Fabianski made a welcome return in goal and 19-year-old Jeremy Ngakia made his Claret and Blue debut, while Robert Snodgrass, Arthur Masuaku, Angelo Ogbonna and skipper Mark Noble all returned to the Scot's starting XI.
Certainly, it was not all doom and gloom for the Hammers in the early exchanges as Ogbonna matched Salah stride for stride before finally conceding a corner and, then the offside Manuel Lanzini gave the home support hope that the hosts could breach the Red defences when he skewed Masuaku's left-wing cross just wide before Ngakia curled another handy centre into Alisson's clutches.
Liverpool had squandered a two-goal lead in their fourth round tie at Shrewsbury Town on Sunday afternoon and, while Jürgen Klopp has controversially declared that the Reds youngsters will contest the replay during the winter break, the German recalled his big guns as he looked to extend the Merseysiders' lead yet further at the top of the tree.
Indeed, only Divock Origi retained the shirt from the weekend's 2-2 draw and, although his cross forced Fabianski into an early, low interception, the Liverpool seniors did not have it all their own way during the opening half-hour.
Midway through the half, Issa Diop had to clear Andrew Robertson's angled shot off the line at the far post but on 35 minutes the Frenchman turned from hero to villain , when Roberto Firmino got the better of the disorientated Ogbonna before picking out Origi inside the Hammers area.
And as the Liverpool striker made his way between Ngakia and the consequently-booked Diop, the No. 23 made contact with an outstretched leg and, following a VAR check, referee Jon Moss awarded a penalty that Salah passed into the bottom right-hand corner as Fabianski headed in the opposite direction.
The Egyptian's 16th goal of the season was sufficient to give the Reds an interval lead in a half where there had not been too much between the two sides by way of goal-scoring opportunities.
But following those relatively routine opening 45 minutes, the game exploded into life at the beginning of the second period as Lanzini forced Alisson into a low save, seconds before Fabianski shepherded Firmino's angled shot beyond his far post.
At the other end, West Ham forced a corner, which Virgil van Dijk headed clear and, although Noble had two decent chances to recycle the ball, Salah eventually won possession on the halfway line before releasing Oxlade-Chamberlain, who shrugged off the retreating Lanzini before slotting past a helplessly exposed Fabianski from 15 yards.
The England wide-boy's sixth goal of the campaign was a Hammer blow to a Moyes' side that had started the half so positively and, indeed, Snodgrass wasted no time in sending Alisson into a low save as he tried to reduce the two-goal deficit.
After Origi saw his angled effort tipped around the far upright for another Reds corner, he was replaced by Fabinho as Pablo Formals also stepped from the bench to replace Lanzini who departed to disgruntled murmurs from the home support.
Still West Ham refused to lie down, though, and Declan Rice unleashed a vicious 15-yarder that sizzled through the Stratford night and with Alisson only able to parry, Trent Alexander-Arnold was the most relieved man in London when his miscued attempt to clear the danger for a corner hit the left-upright before ricocheting to safety.
It was at that point that the luckless Hammers must have realised that any glimmer of hope remaining in the contest had evaporated but they did enjoy a moment's rare fortune when Liverpool struck the woodwork at the right end on 80 minutes, only for Salah's first-time strike to rebound behind.
Rice's hanging header also produced a sensational save from Alisson and, as Liverpool set their sights on all manner of record-breaking opportunities, the Hammers must now produce a similar workmanlike performance against Brighton & Hove Albion in Saturday afternoon's crucial six-pointer.
HAMMERS: Fabianski, Diop, Ogbonna, Cresswell, Ngakia, Masuaku, Rice, Noble, Snodgrass, Lanzini (Fornals 69), Haller. Unused subs: Randolph, Balbuena, Zabaleta, Sánchez, Cardoso, Ajeti.
REDS: Alisson, Alexander-Arnold (Keita 77), Robertson, van Dijk, Gomez, Henderson, Wijnaldum, Oxlade-Chamberlain (Jones 85), Salah, Origi (Fabinho 69), Firmino. Unused subs: Adrián, Lovren, Minamino, Matip.
Booked: Diop (34)
Referee: Jonathan Moss
Attendance: 59,959.
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