Olivier Giroud’s penalty and Aaron Ramsey’s tap-in moved them to the summit, a point ahead of Manchester City and Leicester, following a 2-0 win.
The Foxes could regain top spot if they beat Chelsea this evening but with Manchester United losing at Bournemouth and City struggling to find their rhythm, the Gunners have the title advantage.
In contrast, defeat left hosts Villa marooned eight points from safety at the bottom of the table with manager Remi Garde, who won the title with Arsenal in 1998, facing an impossible job.
They will be bottom at Christmas and face a must-win game at Newcastle on Saturday having not won in a club record 15 league games.
Villa, one of just seven ever-present teams in the Premier League, look all but down even with half the season remaining.
They had not beaten Arsenal at home for exactly 17 years, when they came from 2-0 down to win 3-2 on 13 December, 1998.
That 16-match run, which included Arsenal’s 3-0 win last year, rarely looked in doubt once the Gunners grabbed an eighth minute lead.
The returning Theo Walcott, in for Alex Oxlade-Chamberlain, outpaced Alan Hutton on the right and tangled with the Scotland international in the area.
It took an age for referee Kevin Friend to point to the spot but when he did Giroud sent Brad Guzan the wrong way for his 50th league goal for Arsenal.
Villa’s enthusiastic approach counted for nothing and Rudy Gestede nodded off his own line after Giroud’s header caught Guzan in no man’s land.
Leandro Bacuna ballooned over after Petr Cech flapped at a cross but Arsenal were comfortable and toyed with their hosts. It was a training game for the Gunners as they passed in front of Villa and waited for their time to strike again, which came in the 38th minute.
Ramsey’s strong challenge on Idrissa Gana set the visitors up on the counter attack and Walcott fed Mesut Ozil to dummy and race clean through.
He then squared to Wales star Ramsey, who had made up the ground, to tap past the helpless Guzan.
It was simple but clinical from the Gunners and left Villa floundering but the hosts at least started the second half with renewed vigour.
Cech claimed Carlos Sanchez’s 30-yard strike and Jordan Veretout shot over before Gestede glanced a header wide.
Scott Sinclair then wasted a golden chance on 57 minutes when he planted an unmarked header over from six yards.
Arsenal had eased off from their first-half dominance to give Villa hope and Gana drilled inches over with 19 minutes left.
Jack Grealish – back in the squad after being dropped for two games when he was pictured partying following last month’s 4-0 defeat at Everton – replaced Gana but Arsenal almost added a third on 82 minutes.
Villa allowed Ozil too much time on the right and when Ramsey held up his cross Oxlade-Chamberlain, on for Walcott, saw his effort saved by Guzan before the keeper claimed Hector Bellerin’s injury-time header.
It was the Gunners’ only serious threat of the half but the damage had been done early with Arsenal left to ponder their title challenge and Villa left to fret over their top-flight future.