Bob Charles, the first-day leader, who played with Stockton all four days, was next at 285 after a round of 74.
Rizzo, the first-day leader with a 66, birdied five holes and was at 8-under 136.
Boydston could have been the first-day leader after he played the first 17 holes in 5 under par.
Seven players, including Larry Mowry, the first-day leader, were tied for seventh at 208.
John Paul Cain, the first-day leader, stayed ahead by shooting a 69 that put him at 10-under 135.
Lee Trevino, the first-day leader with $80,000, failed to win a hole on the second.
Ostrega was the first-day leader with 68, but he shot 73 today, as 43 players in the field of 69 made the cut at four-over 148.
Rinker, the first-day leader, shot a four-under-par 68 to go to 13 under.
Nancy Lopez, the first-day leader, failed to win a skin yesterday but finished with $110,000.
Colleen Walker, the first-day leader with 67, shot six-over 77 for a 36-hole total of two-over 144.