(CNN)Arsenal's FA Cup title defense came to an end with a 1-0 defeat by Southampton in the fourth round.
After a poor start to the season, the Gunners appeared to have turned a corner ahead of Saturday's game, having gone six matches without defeat and five without conceding.
But a first-half own goal from defender Gabriel ended that run and helped the Saints progress to the next round.
"I'm really sad to be out of the competition, congratulations to Southampton," manager Mikel Arteta, who led Arsenal to an FA Cup final victory against Chelsea last year, told BT Sport.
"Disappointed to be out and disappointed with the way we lost the game, conceding in an area where we cannot give the ball away."
Arsenal was without captain Pierre-Emerick Aubameyang, who was absent due to a "personal matter," according to Arteta, and instead called upon 21-year-old Eddie Nketiah to lead the attack.
However, it was Southampton, a place above Arsenal in the Premier League table, who showed more attacking intent early on.