Summer Squall, returning to racing after a 14-week vacation, rallied from dead last on the first turn to win the $300,000 Pennsylvania Derby at Philadelphia Park yesterday.

Summer Squall, the 1-5 favorite, had only two horses beaten midway through the backstretch, but jockey Pat Day got the Preakness winner and Kentucky Derby runner-up going and won by 3 3/4 lengths. "He got messed up at the start," said Day, adding that Summer Squall was hit coming out of the gate. "He's very competitive. He showed me courage I had not seen before."

Challenge My Duty, longest shot on the board and ridden by Inocencio Ayarza, finished second by a length over Sports View and Mike Smith.

The colt earned $180,000 (career total $1,510,978) for his ninth win in 11 starts. He ran 1 1/8 miles in 1:48 1/5 under top weight of 123 pounds.

Jerome Handicap: Housebuster rolled past five rivals, including previously unbeaten Citidancer, for a 13-length victory in the $170,100 test for 3-year-olds and up at Belmont Park. The 3-year-old son of Mt. Livermore went a mile in 1:34, four-fifths of a second off the stakes record by Noble Nashua in 1981.

Housebuster lurked just off leader Citidancer, who had fractions of 22 3/5, 44 4/5 and 1:08 4/5. Jockey Craig Perret nudged Housebuster as they straightened for home and he took off. Citidancer, at 114 getting a 12-pound break over Housebuster, held second over D'Parrot.

Secretariat Stakes: Super Abound beat Unbridled, the Kentucky Derby winner making his debut on grass, by three-quarters of a length in the 1 1/4-mile, $250,000 feature at Arlington International Racecourse. The colts, owned by Frances A. Genter, were an entry.

Leading most of the way, filly Super Fan and jockey Shane Sellers put up a game fight in the stretch before finishing third, another 1 1/2 lengths back.

All American Futurity: Refrigerator ran 400 yards in 19.3 seconds to win the $2 million event at Ruidoso Downs (N.M.), the world's richest quarter horse race. The 2-year-old brown gelding battled for the lead out of the gate and outdueled previously undefeated filly Quick Fun, who took second, in the stretch.

Favorite Strait To The Bank veered toward the rail 100 yards into the race, collided with the rail and unseated jockey Jacky Martin.