Arcangelo charged along the rail to victory in the 155th Belmont Stakes on Saturday, making Jena Antonucci the first female trainer to win a Triple Crown race.

Arcangelo surged along the inside past leader National Treasure out of the final turn then raced home in 2 mins, 29.23 secs to give 45-year-old Venezuelan jockey Javier Castellano his first Belmont victory.

Forte, a 2-1 favorite of the bookmakers, was second with Tapit Trice third in the 1 1/2-mile showdown, the last and longest event in American flat racing's Triple Crown for three-year-olds.

Antonucci was stunned at the historic triumph.

"We're just trying to soak all this in right now. Just so proud of the horse," she said. "He's got the heart of a champion. He's just that guy. Just amazing.

"Immense gratitude for this horse for laying it on the line for us."

Regarding her historic place among horse racing trainers, she had a message for those who would take inspiration from her achievement.

"Never give up. And if you can't find a seat at the table, make your own table," Antonucci said. "Build your team and never give up. People see you. Just keep working your butt off."

Castellano had never won the Kentucky Derby until last month when he rode Mage to victory and he had never captured the Belmont Stakes until guiding Arcangelo over the line at Belmont Park.

"I give all the credit to the horse," he said. "It's a wonderful horse and the way he did it today, I don't think this is the limit. Had a beautiful trip alongside the rail."

Castellano said the Belmont triumph was extra special because he and his family live in New York.

"Dream come true," he said. "To win two Triple Crown races this year, I've been blessed. It means a lot to me. We've lived in New York for 22 years."

Smoke from Canadian wildfires that blanketed New York with a thick orange haze had jeopardised the race, producing air quality so hazardous that Belmont Park was closed on Thursday.

Air quality conditions improved on Friday to allow workouts and races and was even better on Saturday for the showcase event.

National Treasure, the Preakness winner, grabbed the early lead and kept it along the backstretch. While rivals challenged from the outside, Arcangelo raced by along the rail.

Kentucky Derby winner Mage, third in the Preakness, was not entered in the Belmont Stakes.

Runner-up Forte was fancied by Kentucky Derby bookmakers before being a late scratch at Churchill Downs due to a foot injury that also kept him from the Preakness.

Forte hadn't raced in 10 weeks as a result of the unexpected lay-off.

Horse safety has been under scrutiny during this year's Triple Crown run after the Kentucky Derby was clouded by a spate of deaths at Churchill Downs that included two on Derby day and eight within three weeks.

At last month's Preakness in Baltimore, Havnameltdown suffered a catastrophic front left leg injury during the sixth race of the day and had to be euthanised on the track at Pimlico Race Course. (AFP)