If only he ran like this at Belmont.

A racehorse escaped from Belmont Park and led a bungling dragnet of cops on a 40-minute chase through a residential neighborhood before being corralled Friday, officials and witnesses said.

The 7-year-old thoroughbred gelding Ambassador Bridge — who last competed at Belmont on Jan. 18 when he came in 11th place — was being trained with several other horses on a field near the main racetrack in Elmont, L.I., when he made his break around 9 a.m.

“He jumped up, and he threw the rider off. [Horses] love this weather, they jump around and go crazy,” said his owner, Leah Gyarmati,49.

The gelding galloped through an open Gate 8 and made his way down Plainfield Avenue near Belmont Park Road and onto Floral Parkway.

“He’s in pretty good shape,” noted Eric Wing, director of communications for the race track.

One witness couldn’t believe her eyes when she spotted the horse.

“There’s a f–king HORSE running loose in floral park by my job. Yes a HORSE with a SADDLE and cops chasing it!” the woman tweeted.

Ambassador Bridge made it about 10 blocks before cops and Gyarmati finally reined him in.

“He dragged the Floral Park Police Department around for a while,’’ Gyarmati said. “So finally, the cops blocked off two or three blocks and attempted to box him in. Finally, after the third try, I was able to get closer and closer.

“You could see it looked like he had enough and was ready to go home,’’ she said.

“He’s a real sweetheart.’’