The Hammers headed into the game at the Boleyn Ground on the back of a 2-0 victory over Arsenal at the Emirates Stadium in North London.
Slaven Bilic’s side were expected to win against relegation candidates Leicester, but they slumped to a 2-1 defeat.
The Foxes went ahead in the 27th minute when Shinji Okazaki found the target, and Riyad Mahrez added the second on 38 minutes.
West Ham stepped up their game after the half-time interval, as Dimitri Payet halved the signing on 55 minutes and Leicester goalkeeper Kasper Schmeichel denied Diafra Sakho.
Schmeichel was also lucky not to be punished for colliding with Sakho inside the area before half time, but West Ham goalkeeper Adrian was not so fortunate.
The Spaniard was sent off late in the game for a challenge on Leicester’s Jamie Vardy after he went up for a corner.
Roberts was following the game, and this was his verdict on the final result:
Leicester top of the league playing good football, but Schmeichel should have given away a penalty & seen a red card, West Ham a bit unlucky— Jason Roberts (@JasonRoberts30) August 15, 2015