Arsenal were dicey in the first half, but recovered well after the break to score twice. And though the last ten minutes after a Swansea City goal were nerve-wracking, the defense was able to hold on to the suddenly-slim lead to give Arsenal a 2-1 win, three points, and the outright league lead. It's September, but that's a lot better than being, say, 12th.
Aaron Ramsey didn't continue his storming form for most of the first half, but after the break he awoke, like a kraken rising from the deep. In the 58th minute, at the end of a good bit of Arsenal passing, Ramsey found young Serge Gnabry cutting in from his place on the right flank. Lt. Serge finished coolly with his right foot, and Arsenal had the lead.
Only about five minutes later, Arsenal were in again. Ramsey started a counterattack, and after some very good play by Olivier Giroud and Jack Wilshere, Ramsey found himself in the box again, with the ball again. He went around a defender and fired a missile into the top of the goal. His run continues. 2-0 to Arsenal.
With only about ten minutes left Swansea scored, as Per Mertesacker was slow to react to a Ben Davies run that led to a goal. But other than that, and one moment of insanity from Wojciech Szczesny, the defense did a job.