For Southampton a reality check, for Arsenal job done. For Artur Boruc, Southampton’s hapless goalkeeper who gifted the home side three points with his ill-timed faffing, a disaster.
Olivier Giroud benefited from two acts of defensive generosity from Southampton - first from Boruc’s gaffe then a clumsy tug from Jose Fonte which gave referee Mark Clattenburg no other option but to point to the spot with five minutes of the game left.
The Frenchman, fresh from helping his country qualify for the World Cup, was chuckling his way up the top goalscorer chart. He now has eight for the season, and won’t score any easier all campaign.
Billed as a top-of-the-table clash between the two form teams of the Premier League, in truth neither side was able to demonstrate what they were capable of.
Southampton, who haven't won a league game against Arsenal since 2002, were too generous little more than a year on from their 6-1 thrashing against Arsene Wenger's men. That day they scored two own goals. This time round, they may as well have done.
The fact it was Arsenal who came away with a 2-0 win and all three points that keeps them at the top in spite of the fact they weren't firing on all cylinders is a testament to where they are. For Southampton their display was a sobering thought for their fans dreaming of Europe.
The return of Theo Walcott, a second-half sub, after two months out, was the cherry on the cake for the Gunners, who will be happy with a job not so done well, but well done.
Arsenal tried to dance, Southampton tried to spoil but neither had their hearts in it. The home side made hay down the visitors’ left flank but the accuracy of their passing couldn't match their ambition.
Similarly for the Saints, Victor Wanyama harried in midfield but did so alone. The Kenyan tip-toed on the boundaries of the law but fought for his side, and pressurized his opponents. Sadly others couldn't say the same.
With centre-back Dejan Lovren out through illness, the south coast club were on the back foot from the off, as were both sets of fans who felt the full force of a seized up London Underground service. Kick-off was put back by 15 minutes.
Jack Wilshere, perhaps the game’s stand-out player, offered a warning of where Arsenal’s threat would be coming from in the first half, working his way into the box from the right and lobbing onto the post from close range early on.
Arsenal were in control of the game, but weren’t exactly tearing their opponents apart. With Bacary Sagna coming to join the party down the right, Southampton were pinned back, and the opener almost came from that side of the pitch when Ozil - otherwise ineffective throughout - crossed low for Ramsey, whose delicious flick rattled the post with 20 minutes gone.
Boruc, who clownishly fumbled around after both chances, also offered a large lump of foreboding with his woeful distribution.
Almost inevitably the game’s first goal came about because of the Pole’s bufoonery after 23 minutes.
Numerous times he had the chance to clear a simple back-pass but every time he chose to try and outsmart Giroud, who was lurking nearby, with a twist and turn. It didn't work. Giroud gleefully accepted the gift. For the remainder of the game, Boruc was the target of ironic cheers from the home support. The least he deserved. Five goals conceded in 11 league games beforehand for Southampton, two needlessly conceded today.
Helped out by a lenient Mark Clattenburg, Southampton tried to get stuck into their opponents but couldn’t get their trademark pressing style started.
Lallana, well shackled by Mikel Arteta, had one of his side’s best chance of the first half but even that was a long-range dipping effort that Wojciech Szczesny palmed over comfortably after the half-hour mark. Rodriguez tested the Pole soon after, who then pulled off an even better save.
Mauricio Pochettino’s side emerged from the break with more energy, but without Luke Shaw, who was replaced by Steven Davies. Later Adam Lallana would come off meaning that Southampton, already without Lovren, were battling the league leaders without their three best players so far this term. No mean feat.
Dani Osvaldo was the man who replaced Southampton’s latest England international and he tried to put the cat amongst the pigeons, most notably with a fine run and shot after 75 minutes. Rodriguez did the same, while at the other end Boruc was rushing madly out of his goal to snuff out an Arsenal attack. It's never quiet with him around.
Arsenal had a few chances of their own, most notably through Wilshere who could only direct his header straight at Boruc, but when Ozil was withdrawn for Nacho Monreal, it looked as though Arsenal were happy to shut up shop.
If the Saints were gearing up for an assault in the last ten minutes the wind was knocked out of their sails when Jose Fonte was penalised for tugging Per Mertesacker in the area. Giroud duly slotted home with five minutes remaining to make it 2-0, and with it secured the game for the home side.
Arsenal will reflect on a good day at the office, where they weren't at their best after the international break but held out against potentially dangerous opposition. They have certainly moved on from their defeat before the international break against Manchester United.
Now four points clear after Liverpool's draw against Everton for the time being at least, they'll look to the busy Christmas period with relish.
Southampton will leave north London scratching their heads. Not for the first time.