Birmingham extended their lead at the top of League One to seven points with a one-sided 4-0 win over basement side Cambridge.

Jay Stansfield gave Birmingham the lead from the spot in the 23rd minute with his 19th goal of the season in all competitions. It came after the hosts won a hotly disputed penalty when James Brophy shoved Ethan Laird.

It was 2-0 when Liam Bennett sliced the ball past his own goalkeeper Nathan Bishop on 39 minutes from Keshi Anderson’s cross.

Kieran Dowell made it 3-0 in the 40th minute, sidefooting home after Anderson dummied Stansfield’s square pass.

Stansfield earned a second penalty in the 57th minute when he was pushed over by Ben Stevenson, but Bishop blocked his effort – ending his perfect record this season, having scored his first seven spot-kicks.

Substitute Luke Harris lashed home the fourth goal from 20 yards with 10 minutes remaining after former City defender Michael Morrison glanced away Scott Wright’s cross.

It was City’s biggest league home win since they beat Reading 6-1 in December 2014 and it extended their unbeaten League One run to 14 games.