Rags to Riches (left), the 22nd filly to run in the 139 Belmont Stakes, stumbled out of the No. 7 gate.
John Velazquez and Rags to Riches (left) rebounded from the stumble to catch up with the pack of 3-year-olds.
Rags to Riches made her move to the outside, while Curlin (right) had to wait to come off the rail.
They made it into a two-horse race a quarter-mile to the finish of the 1 1/2-mile Belmont, staying neck and neck down the stretch.
Rags to Riches edged Curlin by a head, the same margin Curlin beat Street Sense by in the Preakness.
Rags to Riches became the third filly to win the last leg of the Triple Crown, following Tanya in 1905 and Ruthless in 1867.
The Triple Crown win was the first for trainer Todd Pletcher (middle), who was 0-for-28, and Velazquez, who snapped a 0-for-20 drought.