At the 2013 Wimbledon Championships, Mannarino beat Pablo Andújar in the first round, losing only six games. He then reached the singles third round of a Grand Slam for the first time, after his second round opponent John Isner was forced to retire at 1–1 in the first set due to a knee injury. He then beat qualifier Dustin Brown, who had just beaten Lleyton Hewitt to reach the fourth round. He pushed veteran Łukasz Kubot to five sets in his fourth-round match, but ultimately lost, setting up an all-Polish quarterfinal between Kubot and up-and-coming player Jerzy Janowicz.