Arsenal threw away a winning position to draw 2-2 with Premier League rival Swansea following a late goal flurry in the FA Cup third round on Sunday.
In Sunday's other game, Liverpool edged non-league club Mansfield town 2-1 thanks to goals from Daniel Sturridge and Luis Suarez.
At the Liberty Stadium, Michu slotted Swansea ahead with a neat finish in the 58th minute, but Lukas Podolski levelled in the 81st and Kieran Gibbs volleyed Arsenal in front inside two minutes after playing a one-two with Mikel Arteta.
But after Podolski only half-cleared a corner, Danny Graham pounced to equalise in the 87th and the sides will have to contest a replay.
Kyle Bartley had the best chance of the first half for Swansea when he headed against the crossbar and the match only came to life after the break when the intensity increased from both teams.
And it was a substitute, Michu, who broke the deadlock after barely a minute on the pitch.
The Spaniard headed past the defence before slotting the ball past goalkeeper Laurent Koscielny.
Arsenal came close to levelling when Olivier Giroud headed wide, but the goal did come after Swansea failed to clear Theo Walcott's corner.
The visitors went in front after a slick buildup saw Gibbs pass to Arteta, who returned the ball to the defender to blast into the net.
But Arsenal held on to its lead for less than four minutes, with Graham scoring after Kemy Agustien's corner wasn't headed away successfully by Podolski.
In the fourth round, Swansea or Arsenal will play at Brighton, the second-tier side which ousted Newcastle on Saturday.
Which team will win the 2013/14 Champions League?