Liverpool struggled to their second successive Premier League draw as their title jitters got worse, leaving them just three points ahead of Manchester City at the top of the table.
Following on from their nervy 1-1 draw with Leicster City at home last week they finished level on the same scoreline with West Ham at the London Stadium.
Sadio Mane scored after 22 minutes, despite James Milner being offside during the build-up, to put the league leaders ahead, but the hosts were level six minutes later through Michail Antonio.
Liverpool, who have now dropped seven points out of 15 since the turn of the year, enjoyed most of the possession during this game, but they forced precious few clear-cut openings and they lacked the fluency that they showed early in the season.
The Hammers, who are in 12th and 30 points behind the Reds, were full value for the point they earned.
Their seven-point pre-Christmas lead is now down to just three, with City breathing down their necks and looking in ominous form in their weekend win over Arsenal.
The visitors made the breakthrough in the 22nd minute when Adam Lallana collected possession on the right.
He fed Milner in front of the assistant referee, the midfielder was clearly offside, but play was allowed to continue and he capitalised by sending a low cross to Mane, who from in front of goal turned and finished unchallenged past Fabianski.
Yet if Manuel Pellegrini's team were frustrated, it ultimately did not show in their play. They required only six minutes to draw level.
Liverpool's makeshift back four - Joel Matip again started in central defence, with Milner at right-back - switched off as Felipe Anderson played a free-kick to Antonio, who from close range took advantage of both time and space to calmly shoot inside the far left post, beyond Alisson's reach.
By half-time they should have led. From another free-kick, the classy Anderson curled a brilliant cross behind the visitors' defence that Declan Rice ran on to before somehow managing to miss the target with a header from directly in front of goal.
That Liverpool, uncharacteristically during their time under Jurgen Klopp, were so sluggish it will have concerned their manager.
In the second half Xherdan Shaqiri and Divock Origi were introduced to shake up the Reds.
But it was West Ham, whose experienced manager Pellegrini denied Liverpool the title in 2014 when City manager, who continued to threaten as Robert Snodgrass kept the ball in play and Anderson touched it into the path of Noble, who struck narrowly over from 12 yards.
Liverpool grew increasingly desperate, but they still might have snatched victory right at the death.
Origi appeared offside when the ball fell to him in the area, but play was allowed to go on only for the striker, one on one with Fabianski, to shoot tamely straight at the keeper.
Liverpool defender Virgil Van Dijk said after the final whistle: "They (West Ham) were decent, they defended very well. But today was disappointing.
"We could have been a lot better I think but it is what it is. The referee was a bit easy at times but we need to do better as well."
Matip partnered Van Dijk in central defence but the Reds have had injury issues in that department this season and the Dutchman continued: "I think all players who've come in have enough quality to do the job - but when you have a back four that doesn't change that's maybe a little bit easier.
"We take it game by game, we're still top of the league. We're still in the race...so we need to be our best for the rest of the season."