Martin Odegaard's brilliant second-half finish saw Arsenal open their Champions League campaign with a hard-fought but thoroughly deserved 1-0 win away to Napoli on Wednesday night.

Playing for the first time in Europe since losing on penalties in last season's final against Paris Saint-Germain, Mikel Arteta's side dominated throughout at the Stadio Diego Armando Maradona, though they had to wait until the final 15 minutes to break the deadlock.

First-Half Dominance Without Reward

Arsenal's control in the early stages was a sign of things to come. Viktor Gyokeres crossed for Bukayo Saka to acrobatically volley straight at Alex Meret, before David Raya unconvincingly parried away Kevin De Bruyne's long-range drive down the other end.

Napoli were fortunate not to fall behind soon after when Eberechi Eze headed Saka's delivery across for Mikel Merino, who was denied at point-blank range by Meret. Eze dragged wide as Arsenal's grip on proceedings strengthened, while Piero Hincapie's left-sided cross almost caught Meret out at his near post.

Saka then wasted the best opportunity of the first half, blazing over a left-footed finish from near the penalty spot after being slotted in perfectly by Odegaard. Arsenal's 13 shots across the opening 45 minutes were the most they have ever had in the first half of a Champions League away game on record (since 2003-04).

Odegaard Delivers When It Matters

Arsenal's dominance continued after the interval without reward. Hincapie somehow poked over inside the six-yard area following a lovely team move that saw Odegaard scoop for Ben White to head across.

But the Gunners finally found their reward when substitute Christos Tzolis exchanged a neat one-two with Odegaard, who then hammered a left-footed drive from the edge of the area that went in via the post. It was another crucial contribution from the Norwegian, who also scored the winner against Chelsea in the Premier League last weekend.

Noni Madueke should have put Arsenal out of sight with five minutes remaining, but he was denied by substitute goalkeeper Vanja Milinkovic-Savic before Tzolis' rebound attempt was blocked on the line. Kai Havertz then thought he had killed the contest with a tap-in after Milinkovic-Savic spilt Tzolis' effort, though a belated offside flag could not cut short Arsenal's celebrations at the full-time whistle.

Arteta's Squad Depth on Display

Arsenal had certainly matched pre-season expectations so far, winning the Community Shield and all three Premier League matches before this trip to Naples. Arteta made four changes from Sunday's 2-1 comeback victory over Chelsea, but those alterations only further highlighted Arsenal's growing squad depth as they controlled the first half and should have taken the lead.

Saka was particularly wasteful in the first half — his five shots were worth 0.95 expected goals (xG), in comparison to Napoli's 0.12 as an entire team before half-time. Arteta will feel it was a deserved victory, too, after his side accumulated a massive 4.05 expected goals (xG) to Napoli's meagre 0.22.

Pressure Mounts on Allegri

Questions remain for Massimiliano Allegri. Napoli rarely ventured forward in this clash, and the pressure may soon heighten after this defeat followed back-to-back Serie A losses against Como and Inter. The Italian side looked short of ideas and confidence throughout, and their European campaign has started with a whimper rather than a bang.

Arsenal, meanwhile, will take immense confidence from a commanding away performance that underlines their credentials as genuine contenders in this season's competition.