By Chris Harris at Emirates Stadium
Arsenal outclassed Aston Villa to extend their winning run to five matches at Emirates Stadium on Sunday
Santi Cazorla hit the post and, although Villa rallied, two goals in seven second-half minutes ended their resistance.
Giroud returned the favour to Ozil for the first of those, picking out the German for a precise finish. And Theo Walcott put the result beyond doubt at the end of another slick counter-attack.
Cazorla added a fourth from the penalty spot, Hector Bellerin fired a fantastic first goal for the club, and the vast majority of the Emirates crowd went home very happy.
Quite right too. Arsenal look in fine fettle - even without their talisman Alexis - and the consistency Arsène Wenger has craved all season has finally come.
This result sees Arsenal climb back above Tottenham into fifth place - perfect preparation for next week's north London derby.
SETTING THE SCENE
The arrival of Gabriel and the absence of Alexis were the major talking points ahead of this game. The first of those South Americans began his Arsenal career on the bench while the latter's hamstring problem forced Wenger into an attacking reshuffle.
The momentum was all with Arsenal. Four wins in a row - including that morale-boosting triumph at Manchester City - had put the Gunners on the cusp of the top four and into the last 16 of the FA Cup.
The new year had been rather bleaker for Villa. They went into this game without a Premier League goal in eight hours and 42 minutes, but Paul Lambert's side did win on their last visit here - on the opening day of last season.
With Alexis and Danny Welbeck sidelined, Arsenal relied on Walcott for genuine pace, and he was an obvious outlet from the start. Just 56 seconds had elapsed when Aaron Ramsey curved a pass into the England man's path, but Jores Okore got back to block Walcott's shot.
Ramsey himself arrowed a shot wide in the sixth minute and it was no surprise when Arsenal took the lead shortly afterwards.
Ozil was the architect with an exquisite flick that diverted Mertesacker's clearance into Giroud's path. Two Villa players converged on the Frenchman and Giroud almost got the ball stuck under his feet as he approached Guzan, but kept his cool to clip the ball beyond the Villa keeper.
Arsenal were already threatening to overwhelm a Villa side clearly lacking confidence. Over-elaboration cost Giroud a second goal when he opted for a return pass to Ramsey instead of a shot, and Ciaran Clark headed clear after Laurent Koscielny nodded a Walcott cross back across goal.
Arsenal took their foot off the gas briefly and Villa came forward cautiously. But they lacked penetration - Ospina dealt comfortably with a few crosses, Mertesacker kept Christian Benteke quiet and Coquelin tidied up in front of his back four.
The home side looked most likely to score next and Cazorla was inches from doing so when he collected Giroud's pass and held off a challenge to shoot against the inside of the post with Guzan well beaten.
Ramsey tested Guzan with nine minutes of the half left and Ospina was finally called into serious action when Andreas Weimann met Carles Gil's cross with a downward header.
Arsenal had a couple of warning signs at the start of the second half. Benteke, a thorn in their side in the past, fired a snap-shot wide after the ball broke for him inside the box. Benteke headed wide not long afterwards, a reminder that Arsenal needed to keep their intensity high.
In the end, two ruthless counter-attacks in the 56th and 63rd minutes put the dampeners on Villa's hopes of a fightback.
Walcott was involved in both.
He won possession inside his own half, dashed forward and picked out Giroud, who played an inch-perfect pass into Ozil's path. The Germany international took a touch and rolled the ball into the far corner beyond Guzan's outstretched hand.
Ospina started the move for the second with a quick throw to Walcott. The England man fed Cazorla and continued his run towards the box, collecting a pass that was probably intended for Giroud and finishing confidently.
The floodgates threatened to open as Giroud headed Cazorla's free-kick against the bar and, with 20 minutes to go, Wenger gave Akpom another chance to shine.
Within six minutes the young striker had earned a penalty after Guzan brought him down, and the Villa keeper's day went from bad to worse after he stood his ground for Cazorla's penalty, only to palm it into his own net.
Guzan's frustrated kick at his post said it all from a Villa perspective. Arsenal, on the other hand, are upwardly mobile, and they underlined their superiority when Bellerin fizzed a low shot beyond Guzan for his first senior goal.
- Mertesacker (C)
- Bellerin Goal!
- Ozil Goal!
- Cazorla Goal!
- Ramsey 76
- Walcott 70 Goal!
- Giroud 70 Goal!
- Rosicky 70
- Flamini 76
- Akpom 70
- Clark Yellow Card
- Delph (C)
- Sanchez 75
- Gil de Pareja Vicent Yellow Card
- Weimann 65
- Cleverley 65
- Westwood 75
- Sinclair 65
- Agbonlahor 65