The co-leaders were all at 8-under par, although Casey was the only one who was able to complete 36 holes at the Redstone Golf Club. The second round was called by darkness after the field spent all day trying to get the tournament back on schedule.
Winds gusting to more than 40 mph Thursday forced a suspension of play. No one was able to finish 18 holes Thursday and half the field did not even start the opening round until Friday.
Those who played their first round early Friday -- including Ogilvy, Casey and Senden -- were given about 30 minutes of rest before starting the second round.
Casey shot a 66 in the morning and a 70 in the afternoon for his 8-under 136 total. Ogilvy, seeking his third win of the year, opened with a 67 and was 3-under for the afternoon round through 14 holes. Senden started with a 65 and was 1-under through 10 holes in the second round.
Those tied for fourth place at 7-under included Bo Van Pelt, Jonathan Byrd, Henrik Stenson, Tommy Armour III and rookie Colt Knost. Van Pelt was the only one in that group who had finished 36 holes.
Players who had early tee times Thursday, and thus had to play in the high winds, completed the opening round early Friday and then sat idle the rest of the day. They will begin the second round early Saturday, after which the cut will be made and the third round will begin.
Tournament officials said they hope to complete 72 holes by late Sunday.