It was Hall of Fame jockey Jerry Bailey's 15th Breeders' Cup win.
Saint Liam, who won the Woodward Handicap, moved to the outside around the turn for home to catch up with the three leaders before pouring on the steam and hitting the wire in the 1 1/4-mile race in 2:01.4. Flower Alley finished second, and Perfect Drift, making his first Classic appearance, ended third in the 13-horse field for Saturday's race.
Bailey was unhappy in the early going.
"When he broke, he broke out sharply and stayed there for 20 or 30 yards, so instead of saving ground for the first few jumps, I was losing ground," Bailey said.
He didn't smell victory until the backstretch.
"When I turned up the backside, I was really pleased with how well he was traveling and where I was at."
Trainer Richard Dutrow said he was surprised Saint Liam had such a tough time.
"I thought he'd win easier than he did. We had a plan, but you have to have the horse; it's all about the horse. Oh my God, what a day!" said Dutrow said after his second win of the day.
The 5-year-old colt, owned by William and Suzanne Warren, has earned more than $4.6 million in 20 career starts.
Saint Liam paid $6.80, $5.10 and $4.20; Flower Alley, $8.70 and $7.10; and Perfect Drift paid $7.80.