Arsenal increased their lead at the top of the Premier League by making short work of Cardiff without any of the drama that saw Manchester United pegged back last week, though Welsh pride survived intact as Aaron Ramsey was not only the scorer of the first and last goals but the best player on the pitch. The former Cardiff player was applauded for his efforts too, whereas Ryan Giggs had been given a rough reception on his return to the city of his birth. Those 22 appearances for the Bluebirds must have made all the difference.

"The Cardiff supporters were fantastic," Arsène Wenger said. "It would be nice to see that sort of thing much more often in football. They are really proud to be Welsh here, you know." Turning to his own side, the Arsenal manager admitted he never expected to be seven points clear going into December. "I wouldn't have believed that at the start of the season, no," he said. "Especially after losing the first game at home against Aston Villa, no one could have imagined we would be where we are now, but things change quickly. That was another mature performance. We are showing consistency and good concentration, and we still have the desire to improve."

Arsenal could have gone ahead as early as the second minute when Jack Wilshere turned on Ramsey's pass and clipped a shot against David Marshall's bar, and definitely should have gone ahead midway through the first half when Mesut Özil helped on a Ramsey pass to put Olivier Giroud clear on goal. Astonishingly the striker found himself in so much space he stopped in anticipation of an offside flag, one which never came because the assistant referee had judged Giroud to have been onside all the time, possibly because he had missed Özil's touch. By the time Giroud realised he was free to play on it was too late as Steven Caulker had trotted back to cover. The Frenchman on the pitch looked annoyed with the linesman as if he felt a flag should have been raised, while the Frenchman in the technical area flapped his arms in frustration and looked to the heavens in despair.

Cardiff did create an opportunity to take the lead when Fraizer Campbell headed wide from Kévin Théophile-Catherine's cross, but the first half was mostly one-way traffic and there was a certain inevitability about the identity of the player who gave Arsenal the lead on the half-hour. Ramsey had been cheered by the home fans at the start when his name was read out, and he was applauded again when he rose near the penalty spot to divert Özil's cross beyond Marshall with a perfect header. Ramsey kept the celebrations to a minimum against his old club though he could probably have done a lap of honour and still been politely received. It was a goal of which Paul Scholes would have been proud and the midfielder's 14th of the season. Ramsey does not score that many goals with his head, but, as his manager said approvingly, it was a very convincing finish. He had a chance for a second on the stroke of the interval, but took a fraction too long from Giroud's pass and ended up shooting too high.

Ramsey opened the second half by dribbling along the byline on the right and cutting back for Giroud to shoot, only to see Ben Turner block on the goal-line. As if to prove he could be almost everywhere at once the Welshman then came close to repeating the trick on the left. Cardiff's best chance of getting back into the game came when Kim Bo-kyung flicked on Andrew Taylor's cross from the left and Campbell got a downward header on target, forcing a smart save by Wojciech Szczesny low down to his right. There was the merest hint of the crowd getting behind Cardiff when Théophile-Catherine brought another save from Szczesny with a long-range shot, yet there was no sustained pressure from the home side and surprisingly little in the way of defiance. Arsenal always looked likelier to score, though as is their wont they produced plenty of slick approach work and few clear-cut chances.

When Santi Cazorla did get a clear sight of goal from a Wilshere pass he lost his composure in all the excitement and managed only the most feeble of shots. Four minutes from time, just when it appeared the game would peter out quite tamely, substitute Mathieu Flamini – regulation sleeves this time, rolled up to his elbows – did rather better from Özil's threaded invitation by nipping into the area to whip a first time shot past Marshall for his first goal since returning.

When Theo Walcott came on at the end to help Ramsey to a simple second against a tired defence, the final scoreline appeared to mock the difficulties both Manchester clubs have experienced on this ground this season.

"We were playing against the best, and we were not out of our league," Malky Mackay said. "We limited their chances for most of the game, and might have got back to 1-1 but for a fantastic save. We had to go for it in the end, but I make no apologies for that. We have played most of the leading sides now and every time we have been competitive, so that gives me hope we can still be in this league next season."