Hope is a killer. Having watched Liverpool open the door, ever so slightly, in the title race – Arsenal inexplicably slammed it back shut in their own faces.

With the opportunity to cut Arne Slot’s side’s lead to just five points against West Ham, the Gunners blew it.

If Liverpool win at Manchester City on Sunday – they’ll open up an 11 point margin at the Premier League summit. Winning at the Etihad, even considering their current issues, is easier said than done, of course.

Credit to the Hammers. They were diligent, disciplined and brave; well worth their three points.

Graham Potter’s impact since his appointment has been encouraging – this a major step in the right direction.

Title hopefuls Arsenal lost at home in the Premier League for the first time this season

Jarrod Bowen scored with a diving header as West Ham United shocked their London rivals

Mikel Arteta’s side could fall 11 points behind Liverpool on Sunday if the Reds beat Man City

But this was a 90 minutes that brutally exposed Arsenal’s deficiencies; or more pertinently a debilitating injury list that has left their attack on its knees.

The sight of Ethan Nwaneri limping off and Myles Lewis-Skelly – this time rightly – being sent off won’t help Arteta’s selections issues.

Nevertheless, Premier League title races are unforgiving. They offer little sympathy for such complaints – Arsenal found out the hard way here on a chastening afternoon.

They enjoyed plenty of possession but very little cutting edge.

It was similar last week at Leicester until Mikel Merino emerged as the team’s unlikely hero.

Merino’s brace as a makeshift striker at the King Power earned him a start at the head of Arsenal’s attack as Arteta dropped Raheem Sterling.

It’s hard to know what to expect from Merino in his new unfamiliar role as Arsenal’s No 9.

Arteta clearly sees potential. His double last weekend suggests Arteta’s surprise decision to deploy his midfielder as a striker is more than just a hopeful whim.

Midfielder Mikel Merino (right) started as a makeshift striker for Arsenal due to an injury crisis

Spaniard Merino touched the ball 35 times but was unable to register a single shot on target

Yet his showing here screamed reality check. West Ham were entirely happy to let Arsenal dominate possession safe in the knowledge that Max Kilman and Jean-Clair Todibo – and then substitute Konstantinos Mavropanos – had Merino under control.

Moreover, West Ham were threatening when they broke; Aaron Wan-Bissaka, in particular, a danger down Arsenal’s left.

So it was no shock then that Wan-Bissaka instigated West Ham’s winner with a marauding blast down the right flank before finding Bowen – who started the move – who nodded home from close range.

Wan-Bissaka was causing Ricardo Calafiori – restored to the team ahead of Lewis-Skelly – no end of problems.

Indeed, it was no surprise when Calafiori was replaced at left back by Lewis-Skelly just 10 minutes into the second half.

There was shock, however, at Arteta’s decision to replace Rice with Oleksandr Zinchenko – a substitution particularly galling for the Arsenal midfielder when you consider the opposition.

As you can imagine, the away end took glee in Rice’s early departure. The fact their latest academy starlet Ollie Scarles – who is treading the same path as Rice – was having a storming game merely heightened their delight. The 19-year-old looks some prospect.

But any embarrassment Rice may have felt was of little concern to Arteta.

Saturday’s result left Arteta’s Arsenal eight points behind league leaders Liverpool

West Ham’s first victory in five games moved them 13 points clear of the relegation zone

Arteta’s thinking was clear; Zinchenko’s invention and eye for a pass, in theory, would offer Arsenal a different dimension.

Yet it was a further indication of just how stretched Arteta’s squad has become.

If Zinchenko – a left back by trade – is the man you’re pinning your hopes on to change the course of a title race then you’re clutching at straws.

Arteta tried to encourage but you sensed his frustrations. You detected an unease with the natives, too.

That anxiety elevated into fury in the 73rd minute when Lewis-Skelly was sent off, following a VAR call, for bringing down Mohamed Kudus on the halfway line after he was caught in possession by the Hammers attacker.

Originally referee Craig Pawson brandished a yellow, but after consulting his screen upgraded his punishment to a red after concluding the Arsenal youngster had denied Kudus a clear goalscoring opportunity.

The home support were incandescent. Just weeks after Lewis-Skelly was wrongly sent off at Wolves, they cried ‘agenda’ again. But there was no agenda here. Lewis-Skelly got caught and paid the piper.

And in the end it was another case of if, buts, maybes for Arsenal.

The Gunners ended the game with 10 men after substitute Myles Lewis-Skelly was sent off

Craig Pawson initially issued only a yellow card but changed his decision after a VAR review

Maybe City beat Liverpool; if that happens this result won’t feel half as demoralising.

Until then, though, Arsenal have no choice but to suck it up and fear the worst.