Palou had a solid Iowa, with a fifth-place finish in the first race and then a victory (his seventh of the year) in the second race. The Chip Ganassi Racing driver would need an unprecedented collapse to lose the title.

A tornado warning, replete with threatening funnel clouds, made IndyCar drivers' weekend at Iowa Speedway extra memorable.

Palou benefitted from a pair of timely cautions to deny Josef Newgarden and David Malukas and claim Sunday’s Farm to Finish 275. The Spaniard had started from pole after a strong second lap in Saturday’s qualifying, but was overtaken twice by Newgarden during Sunday’s race.