In an otherwise close game, Gabriel's decision to try to block a shot from Kyle Walker-Peters proved decisive for Arsenal losing its hold on the cup.
Right-back Walker-Peters was allowed plenty of space to overlap the Arsenal defense, but his shot looked to be heading narrowly wide of the far post before Gabriel's failed attempt deflected the ball off the post and in. It was the first goal Arsenal had conceded since Dec. 26 after five consecutive shutouts.
"I’m very disappointed because we wanted to continue in the competition, we had a dream to do it again like last year and the dream today is over,” Arsenal manager Mikel Arteta said.
“I am as well disappointed with the way we conceded the goal in an area where we know we shouldn’t be doing that," he added. "At the same time, I cannot fault the effort of the players, how they tried and how they went to get a goal in the second half.”
Arsenal has won the FA Cup a record 14 times and Arteta before kickoff called it “our favorite competition.” Pierre-Emerick Aubameyang scored both of the team's goals in the 2-1 win over Chelsea in last year's final, but he wasn't available Saturday due to what Arteta called “a personal matter.” Arteta said he couldn't yet predict when Aubameyang might return.
Southampton moves on to a fifth-round game away at Wolverhampton, which beat sixth-tier Chorley on Friday.
CITY UNDER PRESSURE
Cheltenham came close to one of the biggest shocks in the 150-year history of the FA Cup before Pep Guardiola's City team scored three late goals.
A long throw-in from Cheltenham captain Ben Tozer caused a mix-up in the City defense and Alfie May seized on a deflection to stab the ball into the net.
In the 81st minute City finally pulled level as Phil Foden met Joao Cancelo's cross at the far post and knocked the ball into the net. Gabriel Jesus scored City's second three minutes later to avoid extra time, though his goal may have been deemed offside if the video review system — not used in cup games at non-Premier League stadiums — had been in operation.
Ferran Torres added a third in stoppage time to ensure City moves on to play Swansea in the fifth round.
Guardiola tried to use the game to give his young players experience, but ended up bringing Cancelo, Ruben Dias and Ilkay Gundogan off the bench.
“The players they brought on from the bench probably tells you something, and the way they celebrated the goals probably tells you something as well," Cheltenham manager Michael Duff said. "I think they’ll know they’ve been in a game.”
The game was briefly interrupted in the first half with the score at 0-0 because of a nearby fireworks display in Cheltenham's red and white colors. Even in defeat, Cheltenham's battling performance against one of the world's biggest clubs will likely become part of local folklore.
SHEFFIELD WINS AGAIN
Premier League clubs Brighton, West Ham and Sheffield United all won their fourth-round games against lower-league teams. Brighton edged out third-tier Blackpool 2-1, while West Ham cruised to a 4-0 win over Doncaster. Sheffield didn't win a game in any competition this season until Jan. 9 but has now won three of its last four following Saturday's 2-1 win over Plymouth.
There is also a rescheduled Premier League game between Aston Villa and Newcastle.