Arsene Wenger felt his Arsenal side were "laboured" and "slow" in the first half of their Premier League clash with Swansea - before they hit back to take all three points.
Swansea, who had won on three of their previous five league visits to the Emirates Stadium, set up defensively but went in at half-time in front thanks to Sam Clucas' first goal for the club. Arsenal had toiled for large parts of the half, with only Alexis Sanchez stinging the palms of Lukasz Fabianski as Swansea's defence held firm.
But - in Wenger's 800th Premier League game in charge - it was a different story after the interval as Sead Kolasinac levelled less than six minutes after the restart before laying on the winner as Aaron Ramsey tucked away his cross to seal a 2-1 win for the Gunners.
"At half-time, I could be worried because we were 1-0 down and I knew that Swansea had conceded only one away goal the whole season," Wenger said.
"For us it was important to play quicker, sharper, with more penetration, changing sides quicker and putting them more under pressure, which we did in the second half. In the first half, we looked dominating but a bit laboured, too slow in our game."
Arsenal moved to just one point behind third-placed Tottenham as a result of their win but face a tough trip to leaders Manchester City next weekend.
Defeat for Swansea means Paul Clement's side could end the weekend in the bottom three if results go against them.
Despite slipping to a sixth league loss of the campaign, the Swans boss was pleased with the visitors' display - but bemoaned their lack of concentration for Ramsey's winner.
"We played well in the first half, it was always going to be a difficult test coming here today," Clement said.
"Arsenal have so many quality offensive players that play those quick combinations in and around the box.
"You have to be focused, not just for 45 minutes but the whole game, I thought we did well in the first half with that and took our chance on the counter-attack where we thought we'd get our opportunities.
"It was just that period after the half where we just didn't get the details right that we got so right in the first period.
"The first goal is a bit of fortune for them because the ball has bounced off a few of our defenders before it has fallen to their left wing-back.
"I was more disappointed with their second goal, I thought we didn't get the details right, we were too open and made some mistakes for that goal."