Slaven Bilic urges two-goal supersub Grady Diangana to prove himself in the Championship

Diangana scored two goals in his first six minutes of second-tier football to turn the game on its head at Kenilworth Road.

Harry Cornick had opened the scoring for Luton in the first half with a free header after Semi Ajayi slipped.

Bilic brought Diangana on at half-time and the 21-year-old drilled a low long-range equaliser into the far corner before capitalising on a deflection to put a diving header past Simon Sluga.

Diangana played 17 league games for West Ham last season, but when Bilic was asked if he was a Premier League player, he said: "There's no point talking about that.

"He's in the Championship, he's got to prove himself in the Championship first.

"He's got quality but it's about consistency. We don't expect him to score two goals every 45 minutes but we can make that pressure be a positive one not a negative one.

"He won't get carried away with this, it's also a part of our job to keep him humble as well.

"The season is a marathon, it's not 45 minutes, his career is a marathon not 45 minutes."

The Baggies improved in the second half when Diangana, Matheus Pereira and Charlie Austin came on.

Diangana came on at half-time for Kyle Edwards, but Bilic was quick to point out it was a team effort that changed the game, rather than just one substitute.

"It was not only him, it was the team, it was a different team," said Bilic. "It wasn't like Kyle out and Grady in, it was the whole team.

"I understand ups and downs, but it could have been a few other players as well (to come off).

"We weren't bad in the first half, we were there, every minute we were coming into good situations, two v one, running into the box and then to create, but we weren't brave enough to do it.

"The final ball was not there or the movement especially was not there.

"So we had a a bit of a spark, one change, and second half it was a different team.

"Players were like 'I want to win this game, turn it around', they were beating the players, passing the ball around. The goals helped of course.

"It was a deflection for Grady's second, but you have to be there, the first half we weren't there. Eventually the ball will hit you or you will hit the ball.

"After that we gained confidence, and they slumped, because they conceded a couple of goals. They were a bit groggy like in boxing.

"We should have used that better to score, but they came back, because they have a good team, and they have belief, but to be fair we introduced a couple more players who are very good on the ball in Pereira and Charlie, and we didn't look like conceding.

"It's a great three points, but we weren't what we wanted to be in the first half.

"We weren't bad, if we were bad we would have made 2 or 3 subs, but we have to be the best against good teams, this is a good team with a manager who likes to play football."

Albion fell behind in the first half to a free header, but Bilic was more disappointed that Martin Cranie's cross wasn't closed down.

Ajayi slipped when tracking his man, although the Baggies protested slightly that he might've been fouled, Bilic disagreed.

"It wasn't a foul," he said. "We have to be closer to the guy, it was a good cross, but we have to be closer with the winger or full back.

"Ajayi slipped, that's why it was a free header, but it wasn't a foul, he slipped.

"I'm not happy but he slipped. We have to close the guy earlier, because he had ages of time. But it was unlucky."