Jamie Vardy’s crisp finish from a lightning break gave Leicester the lead on 18 minutes – but he was then sent off after getting a second yellow card for diving when he tangled with Angelo Ogbonna early in the second half.
Referee Jon Moss made himself even more unpopular when he awarded West Ham a penalty with six minutes left. There had been pushing and pulling in both penalty areas but he decided to punish Wes Morgan for pulling back Winston Reid at a corner.
Substitute Andy Carroll slotted home the penalty and Aaron Cresswell looked to have opened the door to Leicester’s title rivals Spurs with a stunning left-footed finish two minutes later.
As the game went into injury time, Moss produced another controversial decision when he pointed to the spot once more after Carroll made the merest contact with Jeff Schlupp.
West Ham clearly felt Moss had evened things up after earlier decisions in their favour, but Ulloa was not concerned as he took the chance to secure what might yet be a vital point – although Leicester will be without Vardy for next weekend’s home game with Swansea.
Man of the match – N’Golo Kante (Leicester City)