Bryan Mbeumo and Ivan Toney combined to sink West Ham 2-0 and banish any lingering relegation fears for Brentford.
Two second-half goals lifted the Bees 12 points clear of the Premier League drop zone after a Sunday afternoon stroll in the London sunshine.
Mbeumo lashed in the opener after being teed up by Toney, and then returned the favour for his strike partner as Toney grabbed his 14th goal of the season.
For West Ham it was another dent in their fading hopes of a top-four finish, and they were also dealt a potentially massive blow with Thursday night’s Europa League second leg against Lyon in mind when defender Kurt Zouma was forced to limp out of the action midway through the first half.
Zouma had taken a hefty kick to the ankle from Christian Norgaard five minutes earlier and seemingly failed to shake off the knock.
Brentford were still buzzing from last weekend’s thumping 4-1 win at Chelsea and Mbeumo had the game’s first effort on target when he headed Rico Henry’s cross straight at Lukasz Fabianski.
The lively forward then tested West Ham’s Polish keeper further with a fierce drive at the near post.
Then, when Fabianski punched a Christian Eriksen corner which was threatening to curl straight in, Mbeumo lashed the rebound over the crossbar.
Eriksen grew into the match as the first half wore on and his free-kick was headed narrowly over his own crossbar by Vladimir Coufal before Fabianski held the Dane’s low, skidding drive.
West Ham, perhaps showing the effect of Thursday night’s first-leg exertions, threatened only once in the opening half when Tomas Soucek headed a cross from fellow Czech Coufal into the arms of Bees keeper David Raya.
Mbeumo got his reward two minutes into the second half when he latched on to Toney’s clever flick and lashed a fierce angled shot past Fabianski.
Moyes sent on Said Benrahma to face his old club, but before the Algerian could get a meaningful touch, Brentford doubled their advantage with a slick move.
Yoane Wissa fed Henry down the left and the full-back’s cross was steered back across goal by Mbeumo for Toney to head in the simplest of finishes and wrap up a deserved win.
Elsewhere, Kiernan Dewsbury-Hall inspired Leicester to a narrow 2-1 win over Crystal Palace.
The midfielder’s first Premier League goal came after a sublime assist for Ademola Lookman’s opener.
Kasper Schmeichel saved two Wilfried Zaha penalties – after VAR ordered a retake – only for the striker to nod in the rebound from the second which gave Palace second-half hope.
But a leveller never came and the Foxes move above Palace to ninth in the Premier League.