Aston Villa defeated Birmingham City 1-0 in the Capital One Cup third round thanks to a 62nd-minute headed effort from striker Rudy Gestede.

Villa manager Tim Sherwood believes the substitutions at half-time, bringing on Jack Grealish and Jordan Ayew, and the players' performances in general in the second half could have propelled Villa towards a much bigger victory against their local rivals.

After the game, Sherwood said: "It wasn't just personnel at half-time. It was also the way we played. It made the difference.

"It was always the plan to go very direct in the first period.

"If you then came out and looked at their back two in the second period, they were 10 or 15 yards deeper than what they were in the first half. That gave us the space to get in between lines - the likes of Jack Grealish.

"They were worn down in the second period. We found loads of space. We should have won by more.

"I think we deserved to win by a lot more. We were on a hiding to nothing.

"All we can do is come here and get through. We showed a lot of bottle. The boys stuck to it.

"In the second half they were brave enough to get on the ball, look forward, pass it forward - it was great."