Arsenal hold a three-goal advantage over Southampton after 45 minutes of play at the Emirates Stadium.
The hosts went ahead on 11 minutes courtesy of a Jos Hooiveld own goal.
Lukas Podolski fed Kieran Gibbs down the left and the full-back's low shot was well parried by Kelvin Davis, but the ball then rebounded off Hooiveld and into the back of the net from close range.
Podolski doubled his side's advantage with a powerfully-struck free kick on 31 minutes and Gervinho made it three four minutes later with a cool finish from eight yards.
A second own goal - this time from Nathaniel Clyne - completed the hosts' first-half scoring eight minutes before the break.
Southampton pulled a goal back in the dying seconds of the half when Danny Fox capitalised on a mistake by Arsenal keeper Wojciech Szczesny.
The Gunners have been thoroughly dominant and could be leading by a bigger margin, but Santi Cazorla and Per Mertesacker have failed to hit the target from promising positions.
