Calcavecchia, a two-time winner of this event, had a 3-under 67 Saturday; Donald, the 2006 winner, a 66; and Jones a 71. The trio completed three rounds at 6-under 204.
Jose Coceres (68) birdied the final two holes to tie for fourth at 205 with second-round leader Brian Davis, who struggled to a 73 in the third round.
Dudley Hart (72) and Ben Crane (71) are one shot further back, as 15 players are within four shots of the lead.
Calcavecchia has won seven of the previous 10 events in which he owned at least a share of the 54-hole lead.
"I'm hitting a lot of greens, but I'm still two-putting and three-putting a lot," said Calcavecchia, who has struggled with his putting this year.