ARCADIA, Calif. - The 2009 season is fast becoming the 2.0 version of Magnum, the racehorse.\nSince being gelded last fall, Magnum has displayed two of the finest performances of his career at Santa Anita this winter, finishing a game third in the Grade 2 San Pasqual Handicap on Jan. 10 and winning the $200,000 San Antonio Handicap on Sunday.\nThe Grade 2 San Antonio was Magnum's first stakes win since the Grade 3 Lone Star Park Handicap in 2006 and served as a prep to the $1 million Santa Anita Handicap on March 7.\nTrainer Darrell Vienna said that gelding Magnum has made a substantial difference for the horse. Last fall, the 8-year-old Magnum was found to have large testicles that were subject to bruising, Vienna said. That led to the decision to geld him.\nMagnum was dismissed at 16-1 in the San Antonio, the third-longest shot in the field. Ridden by Joel Rosario, Magnum stalked pacesetter Well Armed through a slow pace of 25.26 and 49.54 seconds for most of the race. Rosario urged Magnum closer to Well Armed in early stretch but did not get a response until the final furlong. Magnum ($35.80) trailed by two lengths at the eighth pole, and won by a length, running 1 1/8 miles in 1:49.14.\n"It's good to have a horse you've had for so long come back around," Vienna said. Rosario "had him in the right spot."\nWell Armed, the winner of the Grade 1 Goodwood Stakes last September, held second, finishing a length in front of the multiple stakes winner Tiago, the 2-1 favorite. Dakota Phone and Informed finished in a dead-heat for fourth in a field of eight.\nOwned by Herrick Racing, Magnum has won 6 of 26 starts and $819,249.