NBCSN’s prime-time telecast of the Iowa Corn 300 drew an average viewership of 541,000, making it the network’s most-watched Verizon IndyCar Series race since 2011 at Baltimore.

It is the third consecutive NBCSN telecast of a Verizon IndyCar Series race this season that has attracted more than 500,000 viewers and shown dramatic growth in ratings and viewership compared to 2014.

Viewership of the action-packed race at the .894-mile Iowa Speedway was 22 percent higher than the 2014 race telecast, and peaked at 650,000 viewers during the late-race duel between Ryan Hunter-Reay and Josef Newgarden for the victory. Hunter-Reay became the ninth different winner in 13 races this season and led a 1-4 finish by American drivers.

The July 12 telecast of the ABC Supply Wisconsin 250 at Milwaukee IndyFest (64 percent increase) and the June 27 telecast of the MAVTV 500 (82 percent increase) also recorded substantial viewership gains over 2014.

Average viewership and ratings for all Verizon IndyCar Series telecasts this season are up nearly 10 percent and a continuation of the growth in 2014, when INDYCAR experienced a 25 percent viewership gain over the previous year.

With three races left, the Verizon IndyCar Series championship remains up for grabs. Front-runner Juan Pablo Montoya of Team Penske holds a 42-point advantage over the surging Graham Rahal of Rahal Letterman Lanigan Racing. Three-time Verizon IndyCar Series champion Scott Dixon is 48 points out of first, while Team Penske’s Helio Castroneves and reigning series champion Will Power also are in striking range.

The championship has been decided in the final race for the past nine years, and the GoPro Grand Prix of Sonoma on Aug. 30 carries double points (100 to the winner, 80 for second, 70 for third, etc.).