Grant's 73rd-minute effort, just three minutes after coming on, secured the win in a derby fought by the Championship teams that produced plenty of chances.

United, who made five changes from Saturday's 2-0 win against Millwall, could have been 2-0 up in the opening minutes.

Former Liverpool youngster Rhian Brewster drilled his effort against the foot of the post and debutant Oliver Arblaster's follow-up was blocked by goalkeeper Alex Palmer, one of 10 Albion changes from Monday's 1-1 draw against Watford.

Albion's Alex Mowatt sidefooted wide and Adam Reach delayed shooting before full debutant Reyes Cleary's shot was smothered by goalkeeper Wes Foderingham.

United forward James McAtee then blazed high and wide, while Cleary should have done better in a one-on-one but Foderingham smothered his low drive.

Another Albion chance went begging when Reach's shot was palmed away.

Ex-United forward Callum Robinson's shot on the turn was turned aside by Foderingham before Reda Khadra had two efforts - one saved and the rebound wide.

Foderingham denied Albion again when his superb reflex save foiled Reach's bullet header.

Robinson and Matt Phillips then both hit the top of the crossbar with spectacular shots.

The Baggies eventually made the breakthrough when Grant nodded home Robinson's cross for his second goal in four days before departing injured.

Australian Associated Press