The chestnut son of Trajectory rallied late and drew off in style to capture the 6 1/2-furlong event for Ontario-sired runners in 1:15.29.
Under jockey Corey Fraser, four-year-old Dancer's Bajan finished two lengths in front of Main Executive. No Dilettante was third.
"He showed his class again tonite," said Tiller, who is now a three-time Shepperton winner. "He's a wonderful horse. He's a horse with a big heart."
Tiller also won the event with Forever Grand (2003) and Dave the Knave (2006).
Earlier this year, Dancer's Bajan won the Steady Growth Stakes at 1 1/16 miles. Wednesday's score elevated his career earnings to $677,152. He is now a seven-time winner from 20 starts.
Dancer's Bajan returned $5.90, $3.40 and $2.60, combining with Main Executive ($4.20, $3) to complete an exactor worth $21.60. No Dilettante ($6.30) rounded out a triactor worth $201.50.