Jerkens saddled the 1973 Whitney Handicap winner Onion (defeating Secretariat), 1973 Woodward Stakes and Jockey Club Gold Cup winner Prove Out (defeating Secretariat and Riva Ridge, respectively), and Beau Purple, who defeated Kelso in three of their four meetings.
Trainer Jerkens guided the 1973 Whitney Handicap victor Onion to victory over Secretariat, as well as the 1973 Woodward Stakes and Jockey Club Gold Cup winner Prove Out, which bested both Secretariat and Riva Ridge.  He also trained Beau Purple, who defeated Kelso in three of their four encounters.