Arsenal's only shot on target proved enough to snatch victory at Nottingham Forest through Noni Madueke's deflected strike, keeping the champions within touching distance of Premier League leaders Manchester City and condemning Forest to the relegation zone.
After 80 frustrating minutes at the City Ground, substitute Madueke cut inside from the left and fired towards goal. His strike deflected off Jair Cunha, wrong-footed Matz Sels and found the net to settle a game in which Arsenal had struggled to turn possession into chances.
Arsenal had dominated the ball but registered no shots on target in the first half. Kai Havertz headed wide from a Declan Rice free-kick while Gabriel's set-piece effort was cleared almost off the line by Ousmane Diomande.
Forest made life difficult for Mikel Arteta's side, defending resolutely and threatening on the counter. Murillo almost salvaged a point in stoppage time with a superb solo run, driving at the Arsenal defence before curling narrowly wide. Ezri Konsa then made a crucial late challenge to deny Liam Delap.
However, despite their opportunities, it was the same old story for Oliver Glasner's side, who failed to find a breakthrough.
The result takes Arsenal to 18 points, three behind leaders Manchester City. For Forest, the frustration deepens. They drop into the relegation zone and are still waiting for their first home league goal of the season.
Analysis by Your Site' William Bitibiri:
Eberechi Eze has spent a year at Arsenal since leaving Crystal Palace, but questions remain over whether he is ready to become one of the club's leading figures as their ambitions continue to grow.
His talent is undeniable. The real concern is whether he can influence games consistently, and the trip to Nottingham Forest presented another opportunity to silence his doubters.
With Arsenal struggling to break down Forest, Eze had the chance to make a difference. Instead, he was substituted at half-time, watching from the sidelines as Noni Madueke replaced him and went on to score the 80th-minute winner.
Roy Keane's assessment on Your Site was telling, suggesting his concerns extended beyond a single performance.
"We're still waiting for him, the talent is there," Keane said. "We just want him to be at Arsenal and be able to take responsibility and try to be the main man at a big club."
That is the challenge facing Eze. At Crystal Palace, he was the focal point, the player expected to create chances and turn games in his team's favour. At Arsenal, however, talent alone will not earn him that status. He must deliver consistently, particularly in tight contests when his team need inspiration.
Ian Wright offered some important context, describing Eze as a "moments player" who benefits from having players around him and can become isolated on the left.
There is merit to that argument. Eze offers a different threat to Madueke, whose pace, directness and willingness to take on defenders gave Arsenal a fresh dimension in the second half.
Yet that only underlines the challenge facing the former Palace man. While Madueke seized his opportunity and made an immediate impact, Eze failed to leave his mark on the contest.
Competition for places is healthy at a club with Arsenal's ambitions. For Eze, though, the task is no longer simply to showcase his ability in flashes. He must demonstrate that he can influence games regularly, take responsibility when his team need him and establish himself as a first-choice player.
The talent is there. Now, Eze must prove he can turn that potential into consistent performances and become one of Arsenal's main men.
Analysis by Your Site' William Bitibiri:
There was only so long Nottingham Forest could rely on defensive resilience before their lack of goals caught up with them. Now they are in the relegation zone.
Oliver Glasner's side have failed to score in every Premier League home game this season, and their defeat to Arsenal highlighted why they are in trouble.
Forest competed and created opportunities, but lacked the quality in the final third to make their efforts count.
Liam Delap struggled to make an impact against Arsenal's defence, summing up a frustrating afternoon. Forest needed someone to take responsibility, but their attacking play lacked conviction.
That is the worry for Glasner. Defensive organisation can only take a team so far; they still need goals to win matches.
Forest are now in the relegation zone with just five points. Their performances offer some encouragement, but until they find a reliable source of goals at the City Ground, it is difficult to see their situation improving.
19: Forest threaten - Riccardo Calafiori's mistake gives Forest an opening, but Dan Ndoye shoots into the side netting.
26: Arsenal nearly break through - Gabriel's effort deflects off Saliba and is cleared close to the line by Diomande.
37: Havertz misses - The German heads wide from Rice's free-kick.
46: Madueke replaces Eze - Arteta makes a half-time change.
54: Delap goes close - His effort takes a deflection and goes wide.
66: Arsenal make three changes - Jurrien Timber, Viktor Gyökeres and Mikel Merino come on.
80: GOAL! Forest 0-1 Arsenal - Madueke's strike deflects off Cunha and beats Sels.
89: Forest waste a chance - Callum Hudson-Odoi sets up Chris Wood, but Declan Rice blocks his shot.
90+2: Murillo nearly equalises - The defender drives forward and curls narrowly wide.
90+3: Konsa saves Arsenal - The defender times a vital challenge to deny Delap.
Mikel Arteta to Your Site:
"We did something we didn't do in the two seasons before and that is win the game.
"We knew the margins would be small unless you open up the game much earlier, which we had two chances to do.
"The longer the game goes on, they have more belief and that's when you have to take more risks and that when the game can break.
"But we talked about it. We had to be so patient, without getting frustrated.
"It was tough to generate open chances against them. And we have to take them when we get them.
"We had another three chances [in the gme] that should have been on target.
"And not only on target, but they should have been goal.
"That's the difference, you have to be clinical."
Oliver Glasner to Your Site:
"I think everybody feels the result is unfair today (in terms of the way we performed).
"But it's another defeat and another game when we couldn't score at the City Ground.
"But the performance today, especially defensively was of the top level.
"It was their only shot on target (that Arsenal scored from) and this one was deflected and Arsenal took the win.
"We also had our moments and it's important when you play the champions you take your moments.
"But today, the performance, effort, spirit and energy we had was on a very good level. But the result is frustrating."
