The final round was to begin Sunday afternoon, and officials expected the tournament to end Monday morning. Wet conditions have plagued the event all week and some holes were virtually unplayable Sunday morning, bringing yet another delay.
John Daly didn't stick around for the finish. He withdrew for the sixth time this season after a 6-over 79 in the third round, without citing a reason.
Chopra was leading entering the final round for the first time. He was at 17 under after a third-round 69 at Tesoro Club, where more rain fell early Sunday and led to a 30-minute delay in the resumption of play.
Chopra started on Sunday with a birdie on the par-3 12th. He played his tee ball to that green Saturday night before darkness halted play, and added another birdie at the par-5 16th before making bogey on his final hole of the round.
Baird (65) was at 15 under after moving 14 spots up the leaderboard during the third round. Estes made three bogeys in his final six holes of the third round, but stayed near the lead thanks in part to an eagle on No. 16.
Daly was 4 over for the tournament, five shots worse than anyone else who made the cut. He bogeyed three of the four holes he played Sunday morning.
Shigeki Maruyama (68), Fredrik Jacobsen (67) and Sean O'Hair (69) were tied for fourth at 14 under, while Cameron Beckman (67) was another shot back.
Tommy Armour III, who shared the lead with Estes after each of the first two rounds, shot a third-round 78 and entered the final round eight shots behind Chopra.