Australian Geoff Ogilvy and US veteran Fred Couples headed a crowded leaderboard heading into the final round of the weather-disrupted Houston Open on Sunday. Ogilvy and Couples were among six players who finished the third round on Sunday morning sharing the lead on 11-under-par 205. The third round had been suspended because of darkness on Saturday evening - the after-effects of weather delays on Thursday. The final round began shortly after third-round play was complete. Joining Couples (68) and Ogilvy (69) atop the leaderboard were England's Paul Casey (69), Ryan Moore (67), Colt Knost (69) and Bo Van Pelt (68). Couples, 49, hasn't won on the PGA Tour since a victory here in 2003. His best finish last year was a tie for fourth in this event. Ogilvy is seeking his third victory of 2009 to go with his win in the season-opening Mercedes Benz Championship and the WGC-CA Championship in March. Jason Bohn (66) and Scott Piercy (69) were at 10-under 206, one stroke ahead of a half-dozen players at nine-under 207. Reigning British Open and PGA champion Padraig Harrington (68) and Justin Leonard (69) are among the group at 207. Harrington will be seeking his third straight major title at next week's Masters.