Michail Antonio's second-half finish was enough to see West Ham past Tottenham 1-0 as the Hammers moved into the top four in the Premier League.
The two teams came into Sunday's clash on the back of contrasting fortunes in Europe, Spurs downed 1-0 by Vitesse while David Moyes' side cruised to a 3-0 victory over Genk.
It took until the 72nd minute for Antonio to break the deadlock at the London Stadium, his sixth top-flight goal against Spurs seeing West Ham move above their rivals.
West Ham, at least temporarily due to Manchester United facing high-flying Liverpool later, climb from seventh into the Champions League spots as Moyes' men continue to prove their quality.
Pablo Fornals' acrobatic right-footed volley forced the first save of the contest before the Spain international skewed wide as the hosts started the brighter of the two sides.
Son Heung-min responded with a low drive, one Lukasz Fabianski saved, after Lucas Moura had wastefully fired off target following the South Korea forward's offload.
Tomas Soucek then headed narrowly wide, with Fabianski subsequently producing a magnificent save to deny Harry Kane's headed effort on the stroke of half-time.
Tempers flared just before the hour-mark as Cristian Romero and Fornals clashed with one another in an otherwise somewhat uneventful start to the second half.
Fornals almost opened the scoring but his right-footed strike, via a deflection off Eric Dier, was tipped over by Hugo Lloris.
However, the Spurs goalkeeper was powerless to stopping Antonio from Aaron Creswell's resulting corner as the forward turned into the bottom-left corner from close range.
The visitors searched for a late equaliser but failed to breach the hosts' defence as West Ham made it three league games without defeat against their London rivals for the first time since May 2006.