Nathan Ake was Manchester City’s unlikely hero as Pep Guardiola won his latest battle with former protege Mikel Arteta, a 1-0 FA Cup victory over Arsenal at the Etihad Stadium.
In a fourth-round battle between surprise Premier League leaders Arsenal and a second-placed City side who are clinging to their coat-tails in the top flight, it was defender Ake who made the difference on Friday.
He delivered the breakthrough in the 64th minute, with a sharp side-footed finish finding the bottom-right corner, out of the reach of goalkeeper Matt Turner.
The top two have still to meet in the Premier League this season, with this tie a taste of what is to come when those games take place in February and April.
Guardiola’s City began strongly, but Arsenal had a big chance in the fifth minute when Takehiro Tomiyasu’s powerful strike from just inside the penalty area was palmed away by Stefan Ortega.
Tomiyasu was then on hand at the other end to keep out Erling Haaland after the striker looked to loop an overhead kick past Turner, who had raced off his line to make an interception.
Arsenal’s new winger Leandro Trossard was denied by a smart save from Ortega after taking on City right-back Rico Lewis and lashing a left-footed strike towards the far corner.
Kevin De Bruyne sent a curling shot from just outside the penalty area a yard wide of the left post, while City suffered an injury blow just before half-time as John Stones went off with an apparent hamstring problem.
Early in the second half, Turner reacted sharply to push away a low cross from De Bruyne that was intended to tee up Haaland for a tap-in
City introduced Julian Alvarez and Kyle Walker just before the hour mark and began to look sharper. Alvarez went close by hitting the right post, a mere 10 seconds before Ake slotted City ahead with a composed finish.
Arteta called on reinforcements, with captain Martin Odegaard among the players sent on from the Arsenal bench, but the Gunners could not force a replay.
Man City player ratings (4-3-3)

GK: Stefan Ortega – 8/10 – Needed to make saves from the start, keeping City in it when Arsenal were arguably stronger in the first half. Stayed strong throughout and never looked as though he was going to be beaten.
RB: Rico Lewis – 6/10 – Spent a lot of time in the middle of the pitch as per instructions from his manager. Clearly a good player but it gave Trossard too much space, albeit not his fault.
CB: John Stones – 5/10 – Often looked vulnerable because of how Lewis was playing. A suspected hamstring injury then ended his night before half-time.
CB: Manuel Akanji – 7/10 – Had to switch positions after Stones was taken off but put in a dominant performance regardless.
LB: Nathan Ake – 8/10 – Finished with great composure to put his team ahead and put in a solid defensive shift as well, with Saka hardly given a sniff.
CM: Kevin De Bruyne – 5/10 – Narrowly missed with a great curling effort in the first half and slightly improved after half-time but was far from his best.
CM: Rodri – 5/10 – Unusually sloppy with the ball by his standards.
CM: Ilkay Gundogan – 6/10 – Did both sides of the ball pretty well but not always on the same page as the forwards ahead of him.
RW: Riyad Mahrez – 4/10 – Not really himself. Didn’t have enough of the ball to make any real impact and was withdrawn before an hour had passed.
ST: Erling Haaland – 5/10 – Attempted the spectacular early on and also took a whack to the back of the head before half-time. Didn’t get his usual quality service.
LW: Jack Grealish – 6/10 – Gets an assist for his layoff to Ake and City’s best forward on the night.
Substitutes
SUB: Aymeric Laporte (45+4′ for Stones) – 7/10
SUB: Julian Alvarez (58′ for Mahrez) – 7/10
SUB: Kyle Walker (58′ for Lewis) – 7/10
SUB: Bernardo Silva (75′ for De Bruyne) – 6/10
Manager
Pep Guardiola – 7/10 – The way he set up the team didn’t make sense when Trossard kept causing problems down City’s right. Changed shape early in the second half and the substitutes definitely did make a positive impact overall.
Arsenal player ratings (4-3-3)
GK: Matt Turner – 6/10 – Stood little chance with the only goal. Always keen to come for crosses or rush off his line.
RB: Takehiro Tomiyasu – 6/10 – Had the first early chance with a good foray forward.
CB: Rob Holding – 5/10 – Got physical with Haaland and took a yellow card for it with 50 minutes still left to play. The danger of getting another saw him removed at half-time.
CB: Gabriel – 6/10 – Did enough to put Haaland off in a key moment.
LB: Kieran Tierney – 6/10 – Would have expected a tougher test from Mahrez. Didn’t offer much going forward to take advantage of that.
CM: Fabio Vieira – 5/10 – Had one shot that missed the target and didn’t do enough otherwise.
CM: Thomas Partey – 5/10 – Didn’t stand out and was surprisingly replaced at half-time.
CM: Granit Xhaka – 6/10 – Successful in stopping City play their usual sparkling game, although a couple of hesitations in key moments were almost costly.
RW: Bukayo Saka – 4/10 – Just 23 touches of the ball tells its own story.
ST: Eddie Nketiah – 5/10 – Couldn’t find the target with a chance in thef first half. The service wasn’t there for him and he touched the ball only slightly more than Saka.
LW: Leandro Trossard – 7/10 – Gave City real trouble from the start and created a number of chances in the first half. Much quieter after the break.
Substitutes
SUB: William Saliba (46′ for Holding) – 6/10
SUB: Albert Sambi Lokonga (46′ for Partey) – 6/10
SUB: Gabriel Martinelli (66′ for Trossard) – 7/10
SUB: Oleksandr Zinchenko (66′ for Tierney) – 6/10
SUB: Martin Odegaard (74′ for Saka) – 5/10
Manager
Mikel Arteta – 6/10 – Took no risks with Holding on a yellow card and later responded to going behind by making chances immediately. Couldn’t get one over on his old mentor.