Champion filly Songbird made a winning return with another dominating performance in the G2 Summertime Oaks at Santa Anita.

Songbird had been sidelined since her victory in the G1 Santa Anita Oaks after developing a fever.

Only four other fillies lined up against Songbird.

Bellamentary went to the front to set the pace with Mike Smith rating Songbird just behind her in second as the field raced through the clubhouse turn and entered the backstretch.

Midway through the backstretch Smith eased Songbird alongside Bellamentary, then began to open up a slight lead heading into the far turn.

Songbird continued to widen her lead through the far turn, eventually cruising under the wire to win by six and a half lengths under a hand ride.

Songbird, purchased for $400,000 at the Fasig-Tipton Saratoga yearling sale by Fox Hill Farm, is now undefeated in eight starts for trainer Jerry Hollendorfer, earning more than $US2.1 million.

"It scares me to think of how good she is," Smith said. "I try not to think of it.

"It's just amazing, her cruising speed. She started lengthening her stride on the backside, and I looked over at Bellamentary and she was having trouble keeping up."

The win was the perfect present for Hollendorfer on his 70th birthday.

He promised to keep challenging Songbird but not against the opposite sex for now.

"It was beautiful. I was very happy with the way she looked going down the backside," he said.

"The opportunity presented itself to be just a little off the pace and now we've shown everyone that we can do that.

"We'll try to keep her doing bigger and better things. I think we'll stick with the girls for now and see what happens."

• At Churchill Downs the G1 Stephen Foster Handicap was won by Bradester, trained by Eddie Kenneally and ridden by Joe Bravo.

It was the first G1 win for the six-year-old as he led all the way on his first attempt at the trip, holding off the fast-finishing Eagle to score by half a length.

"He does all the hard work for you," Bravo said. "He kind of reminds me of his father Lion Heart, who I rode in the Haskell. I just kind of rode him like his dad and you saw what he did."