The Hammers’ attacker was in the right place at the right time to convert from six yards out 20 minutes into the second half.
Harry Kane had earlier seen his low drive somehow saved by Hammers goalkeeper Adrian, but that turned out to be our clearest opportunity as the home side stopped us from playing on our first visit to their new London Stadium base.
Indeed, Slaven Bilic’s men remained defensively well-organised, hunted in packs and always seemed to have a mass of players behind the ball to prevent us from breaking through.
It was only our fourth league defeat of the season and means we remain four points behind Chelsea in the title race, the Blues not playing until Monday evening when they entertain relegation-threatened Middlesbrough.