Aston Villa manager Paul Lambert has vowed to keep fighting despite seeing his side slip to a second embarrassing cup exit in the space of three days.

A late John Marquis header condemned Villa to a fourth-round FA Cup defeat at npower Championship Millwall after they were humbled by League Two side Bradford in the Capital One Cup semi-finals on Tuesday.

The game was marred by a section of Millwall supporters during the second half, with some throwing bottles at assistant referee Mark Scholes and police making three arrests.

Darren Bent, recalled to the Villa line-up with Christian Benteke rested, put Lambert's side ahead after 22 minutes but an equaliser from Lions captain Danny Shittu and the dramatic winner from Marquis capped a difficult week for the former Norwich boss, who is determined to remain positive.

"There did not look to be a hangover (from the Bradford defeat)," he said.

"They have always been pretty upbeat and are not a group that go down really quickly, I don't have the problem of lifting their spirit.

"There are two ways to deal with it, you either accept it or come out fighting and I will keep fighting because I'm brought up that way.

"I handle it in my own way, I've got to handle it - you are the custodian of the football club and I will try everything I can to turn it around."

The two cup setbacks come with Villa languishing 17th in the Barclays Premier League, with top-flight survival still top of Lambert's agenda.

"The lads have played a hell of a lot of games and we've not got the biggest of squads. You have to watch what you're doing," he said.

"You can't make too many changes but the Premier League is the most important thing."

Fellow strugglers Newcastle await on Tuesday and Lambert said: "It is a massive game and that's why I left Christian and a few others out for this match."

Lambert blamed individual errors for the loss, something he admits is frustrating.

"When you go one up and lose a goal from a corner again, it is individual errors that are hurting us at the moment," he said.

"You've got to learn, you've got to be prepared to get hurt in your penalty box and we aren't - that is the disappointing thing."