Trump said his Dallas Republican midterm convention was a sold-out success that "beat the NFL" in overall numbers and set an attendance record for the arena.
On Truth Social, he said the venue was packed, thousands more were left outside watching on screens, and he would return the next night to close the event.
The report offered no independent audience figures, noting ratings for the NBC NFL opener were not yet available when Trump made the claim.
The boast framed the convention against the season's first NFL game, turning a political rally into a direct ratings comparison with one of U.S. television's biggest draws.