Match ends, Oxford United 1(4), Sunderland 1(2).
Oxford United beat fellow League One side Sunderland on penalties to reach their first League Cup quarter-final since 1987-88.
Will Grigg missed his penalty for the Black Cats, with U's keeper Simon Eastwood saving Marc McNulty's kick to win the game.
The U's had led through Rob Hall's curling effort from the edge of the box, moments after McNulty hit the bar.
McNulty levelled for Sunderland from close range to force the shootout.
The U's were hanging on at the end of the 90 minutes, although Sunderland's goal was their only shot on target.
Karl Robinson's side, who scored all their penalties, also beat Millwall on penalties in the second round before beating West Ham 4-0 last time out.
The quarter-final draw will take place on Thursday at about 08:45 GMT on BBC Radio 2's Zoe Ball Breakfast Show.
'We were poor today'
Oxford boss Karl Robinson:
"It's out of your control when it goes to a penalty shootout.
"It's more about the players and fans that turned out. You never plan to win that way but if you're going to win and go to the quarter-finals of a competition like this that's the best way to do it.
"We were poor today. That's probably the worst we've played. But what a tremendous testament to League One."
Sunderland manager Phil Parkinson:
"The referee has to take a long hard look at himself for two penalties tonight.
"There was a clear penalty in the first half when Joel Lynch was pole-axed in the box.
"The second one - I can't see how it has not been given. Luke O'Nien was just about to pull the trigger and score or attempt to score - there's not a great deal of contact, but it's enough to bring him down and the referee was only 10 yards away.
"Everybody in the ground saw that was a penalty, so it's hugely frustrating. The game should have been out of sight anyway. Those incidents should be irrelevant."
- 16BaptisteSubstituted forMousinhoat 90+3'minutes
- 7HallSubstituted forFordeat 81'minutes
- 9TaylorSubstituted forMackieat 81'minutes
- 3LynchSubstituted forGriggat 56'minutes
- 33HumeSubstituted forO'Nienat 68'minutes
- Steve Martin
- Shots on Target
Penalty Shootout ends, Oxford United 1(4), Sunderland 1(2).
Penalty saved! Marc McNulty (Sunderland) fails to capitalise on this great opportunity, right footed shot saved in the bottom right corner.
Goal! Oxford United 1(4), Sunderland 1(2). John Mousinho (Oxford United) converts the penalty with a right footed shot to the high centre of the goal.
Penalty missed! Bad penalty by William Grigg (Sunderland) right footed shot is high and wide to the left. William Grigg should be disappointed.
Goal! Oxford United 1(3), Sunderland 1(2). Tariqe Fosu-Henry (Oxford United) converts the penalty with a right footed shot to the top right corner.
Goal! Oxford United 1(2), Sunderland 1(2). Luke O'Nien (Sunderland) converts the penalty with a right footed shot to the bottom right corner.
Goal! Oxford United 1(2), Sunderland 1(1). Anthony Forde (Oxford United) converts the penalty with a right footed shot to the bottom left corner.
Goal! Oxford United 1(1), Sunderland 1(1). Max Power (Sunderland) converts the penalty with a right footed shot to the top left corner.
Goal! Oxford United 1(1), Sunderland 1. James Henry (Oxford United) converts the penalty with a right footed shot to the bottom left corner.
Penalty Shootout begins Oxford United 1, Sunderland 1.
Second Half ends, Oxford United 1, Sunderland 1.
Substitution, Oxford United. John Mousinho replaces Shandon Baptiste.
Corner, Sunderland. Conceded by Sam Long.
Foul by Jamie Mackie (Oxford United).
Luke O'Nien (Sunderland) wins a free kick in the defensive half.
James Henry (Oxford United) wins a free kick in the defensive half.
Foul by Aiden McGeady (Sunderland).
Attempt missed. Jamie Mackie (Oxford United) right footed shot from the centre of the box misses to the right. Assisted by Tariqe Fosu-Henry with a cross.
Foul by Jamie Mackie (Oxford United).