A late goal by Alexandre Lacazette was needed for Arsenal to see off a spirited Cardiff side who twice came from behind to peg back the Gunners.
Another Petr Cech wobble and a Granit Xhaka mistake makes for familiar reading in the team player ratings, whilst Lacazette's first start sees him produce a man of the match performance.
Defence still learning
Petr Cech - 6/10
Still looks very awkward playing out from the back. The instructions to play out from the defence seem to cloud his judgement as to know when to kick long. He gave the ball to Harry Arter very cheaply, who wasted a good opportunity. There wasn't much he could do about the Cardiff goals. Bernd Leno’s first start must be on the horizon.
Hector Bellerin - 6/10
Looked better defensively than in previous weeks and his pace going forward caused problems in the first half. Lack of defensive cover enabled Joe Bennett to have time to pick his cross for the first Cardiff goal.
Shkrodan Mustafi - 7/10
Bullet header for the opening goal and nearly had another in the second half. Some quality passes out from the back allowed Arsenal to dominate possession throughout the match. A few commanding headers and clearances but when defending as a unit the Arsenal back four looked weak and unorganised.
Sokratis Papastathopoulos - 6/10
A stable performance at the back, he made no grave errors which seems like a miracle in this Arsenal backline. Work still needed in his partnership with Mustafi.
Nacho Monreal - 6/10
Not his usual potent threat going forward as he missed a good chance one-on-one. He didn't add much defensively either. Should have done better picking up Victor Camarasa for the first Cardiff goal.
Midfield can improve
Granit Xhaka - 6/10
Flashes of brilliance, including a superb delivery for Mustafi to head home. Poor judgement let him down though which a ridiculous attempt at a cross field ball allowing Cardiff the perfect platform to score their first goal. More composed performance than against West Ham but still not reliable.
Matteo Guendouzi - 6/10
A standard performance for Guendouzi, not reaching the heights of his opening two games. Seems to be tiring and rightly deserves a rest. Time to let Lucas Torreira take his place.
Mesut Ozil - 6/10
Offered nothing in the first half offensively or defensively. Just after the hour mark took slightly more control of the game and started to drive Arsenal forward.
Aaron Ramsey - 7/10
A hungry performance from the Welshman who revelled in the number ten role. Looked busy throughout trying to link up the play. Arsenal need him to sign a new contract as he will be an important player as ever this season.
Pierre-Emerick Aubameyang - 6/10
Off the pace and looked short of confidence in the first half. Seemed unsure of his role out on the wing and it felt unnatural. However, he combined brilliantly with Lacazette to score his first goal of the season and what a finish it was.
Alexandre Lacazette – 8/10
Followed up his strong performances from the bench this season with a fine game in his first start under Unai Emery. He looked sharp throughout and was keen to bring others into play, highlighted by his delightful flick to set up Aubameyang. Denied by the post in the first half but a smart turn and powerful finish saw him net the winner and his first goal of the season.
Lucas Torreira - 7/10
Calm and composed on the ball which had a ripple effect throughout the team. Always seems to know where the danger is and sniffs it out. A brilliant assist for Lacazette. Must start.
Not enough time to make an impact, but clearly liked by Emery who sees him as a useful substitute.
Henrikh Mkhitaryan 6/10
Only played a meagre 4 minutes. Not enough time to have any impact.