Another try followed from the Ospreys' next attack, Mike Phillips looping around to find Lee Byrne at pace and the full-back handed off Webster to send Tommy Bowe down the touchline.
Lee built up exceptional pace on a helpful pitch, while Mark Boucher and Jonty Rhodes batted cautiously until the latter was caught off Warne, who took two for 10 in his last seven overs.
Last week's Bridgestone Invitational winner Adam Scott is among three players just three shots off the lead, while world No.2 Lee Westwood is four off the pace after a 68 and world No.1 Luke Donald is six behind after carding a 71.