Arsenal will stay top at least until Monday's match between Manchester City F.C., who they knocked off the summit, and third-placed Chelsea at the Etihad Stadium.
Arsenal F.C. have 55 points from 24 games, followed by City on 53 from 23 and Chelsea F.C. on 50 from 23.
Liverpool F.C., who were held to a 1-1 draw at West Bromwich Albion on Sunday, are fourth with 47 points.
Palace, who have improved since Tony Pulis became manager at the end of November, remained just a point above the relegation zone.
Oxlade-Chamberlain, playing in central midfield rather than on the wing as usual, had a fine game in his first league start after returning from a long injury layoff.
He opened the scoring with a clever lofted shot after 47 minutes, his first goal of the season, and doubled Arsenal's lead in the 73rd minute, firing home after a neat one-two with Olivier Giroud.
A dreadful mistake by defender Kolo Toure cost Liverpool F.C. victory when he gifted West Brom the equaliser in a 1-1 draw.
Under no pressure, the defender played a loose ball straight across his own 18-yard line to substitute Victor Anichebe who was unmarked on the edge of the box and he fired home in the 67th minute.
Liverpool F.C. went ahead in the 24th minute when Daniel Sturridge tapped home a cross from Luiz Suarez.