Reigning, a horse that ended his previous campaign in a 3200m race, returned for new trainer Bart Cummings with a shock win over a much shorter course at Warwick Farm on Saturday.

Reigning, formerly trained by Con Karakatsanis, resumed in The Castaway Handicap (1400m) and arrived in time to win by a half neck as a $41 outsider.

Stable foreman James Cummings said the victory came as a surprise.

"I guess it goes to show when they look really well, they do run well," Cummings said.

"We said to the owners he wasn't necessarily a strong betting proposition today.

"That's just an excellent start to his campaign and we can't wait to see what comes."

Reigning raced in the Queensland Derby (2400m) last preparation before placing in the Stayers' Cup (3200m) at Rosehill, although he was beaten 15 lengths.

Cummings said the four-year-old could mature into a nice middle-distance horse.