Arsenal launched a stunning second-half comeback to beat Aston Villa 3-2 in the FA Cup fourth round tie at The Emirates.
Villa were 2-0 up at half-time thanks to a Richard Dunne header and a fine Darren Bent goal just before the interval.
However, Arsene Wenger's men roared back to win, thanks to two second-half Robin Van Persie penalties and a fortuitous Theo Walcott goal.
Arsenal will travel to Sunderland or Middlesbrough in the fifth round, on the weekend of the 18/19 February.
The visitors took the lead on 33 minutes, thanks to Villa's Irish connection.
Stiliyan Petrov's backheel after a corner set up Robbie Keane to cross for Dunne to power in a header past Arsenal goalkeeper Lukasz Fabianski and a ball-watching Gunners' defence.
Alex McLeish's men made it 2-0 just before half-time.
Another Irishman, Stephen Ireland, fed Bent and though the England striker's angled drive was parried by Fabianski, Bent squeezed home the rebound from an acute angle.
The Emirates erupted into a wall of boos, but they soon turned into cheers in seven crazy second-half minutes.
The Gunners were awarded a penalty on 54 minutes when Dunne fouled Aaron Ramsey as the Welshman ran onto Alex Song's through-ball.
Van Persie sent Shay Given the wrong way to make it 2-1. Within two minutes, Arsenal were level, as Alan Hutton smashed a clearance back against Walcott and into the net.
Referee Mike Jones then pointed to the spot for a second time on the hour, after Bent fouled Laurent Koscielny on the edge of the Villa box.
Van Persie again did the honours, netting his 25th goal of the season. All through that seven minutes, manager Wenger sat impassively. One can only guess at the reason why, but perhaps the Frenchman was making a none-too-subtle point to the fickle home fans.