Favorite Heir, at 1-5, won Gulfstream's sixth race to open the Rainbow 6.
Bettors added $405,862 on the Rainbow 6. The carryover coming into the day was $2,273,704.
The carryover has been growing because Thursday was the 36th straight day of the "jackpot" requirement of just one ticket with the winners of all six Rainbow 6 races.
The sixth race was 7 1/2 furlongs on turf for maiden claimers, with a $25,000 claiming price. Favorite Heir won in 1:28.79, a solid time for that level.
Javier Castellano rode Favorite Heir, for trainer Milt Wolfson.