The Hammers signed Antonio from Nottingham Forest last summer, after the club’s recognised his talents while he was playing in the Championship.
Bilic initially showed reservations over using the winger, and he played him just once up until December.
However, after injury struck, Antonio was given his chance and he has not looked back.
The 25-year-old has been a revelation since breaking into the Hammers’ starting line-up, and he scored the winner in Bilic’s side’s most recent match against Tottenham Hotspur.
And the Croatian boss said: “I have been delighted with Michail Antonio, who scored the winning goal against Spurs, since he came into the team. He has improved a lot since he came here.
“He is a quick learner but when you look at his history — he started out at Tooting & Mitcham — he had no other options than to learn. I didn’t know him before he came here but I have learned his story since.”
Antonio has now made 16 Premier League appearances for West Ham, and he has scored five times.
Despite having to play at both full-back and down the wing, Antonio has looked fully comfortable with playing in the top tier.
Antonio is now an established part of Bilic’s starting line-up, and West Ham will be relying on him to keep his good form up.
The Hammers are in the thick of the battle for a Champions League qualification space, with their next match coming against Everton at the weekend.