Jockey Tammi Piermarini celebrated her 48th birthday by guiding favored Bluegrass Singer to victory in the inaugural running of the $75,000 Parx Derby on Saturday at the suburban Philadelphia track. Formerly based at Suffolk Downs, Piermarini was riding Bluegrass Singer ($4.20) for the first time. She positioned her mount just off the early pace of 48.59 seconds set by 15-1 outsider Mr Discreet. Bluegrass Singer surged to the front approaching the final turn, took a 2 ½-length lead in midstretch, and held off 2-1 second choice Unrivaled to prevail by three-quarters of a length. Unrivaled, ridden by Frankie Pennington, might have cost himself the win by drifting in and out during the stretch run. Dontbetwithbruno, trained by Todd Pletcher, finished third at 5-2 in a field reduced to five 3-year-olds by a pair of scratches. The winning time for a mile and 70 yards was 1:45.08. Bluegrass Singer, trained by Marcus Vitali, spent the winter racing at Gulfstream Park, where he won the $100,000 Mucho Macho Man and finished third behind Kentucky Derby runners Upstart and Frosted in the Grade 2 Holy Bull. He was making his first start since finishing fourth in the Grade 2 Swale nearly two months ago. He now has won 4 of 11 starts for Cross Sabres Farm. In the co-featured $75,000 Parx Oaks for 3-year-old fillies, Danzatrice upset Grade 1 winner By the Moon, rolling to a 4 1/4-length victory. Trained by Cal Lynch and ridden by Trevor McCarthy, Danzatrice ($13.80) is a head shy of being unbeaten, finishing second in her second career start last October. She easily won her 3-year-old debut in March at Laurel Park. By the Moon, winner of the Grade 1 Frizette last fall and easy winner of the Caesar’s Wish at Laurel in March, was a clear-cut second as the 3-5 favorite, finishing two lengths clear of Stroke Play, who did well to finish third after being forced to check severely to avoid clipping another horse’s heels at the three-eighths pole. The winning time of 1:44.71 was faster than 3-year-old colts ran earlier on the card in the Parx Derby. In the other $75,000 stakes, both restricted to Pennsylvania-breds: A Fleet Attitude ($15.20) outfought Kobel and Yougotthatgoinforu in deep stretch to win a three-horse photo in the seven-furlong Lyman Handicap. The 5-year-old A Fleet Attitude, ridden by Angel Castillo for trainer Richard Vega, was making his first start since December. He got up by a head in 1:24.09. Kobel nosed out Yougotthatgoinforu for second. Power of Snunner ($8), cutting back to seven furlongs after a 10 1/2-length romp going two turns, rallied from fourth in deep stretch to draw clear by 4 1/4 lengths in the Foxy J.G. for fillies and mares. Ridden by Matthew Rispoli for trainer Tim Kreiser, the 5-year-old Power of Snunner is now 6 for 19 lifetime.  She ran seven furlongs in 1:24.52.