In July 2007, Hayden made his MotoGP début as a wild card for Kawasaki at Mazda Raceway Laguna Seca.

On September 16, 2007, at Mazda Raceway Laguna Seca, Hayden clinched the AMA 600 Supersport championship after finishing runner-up twice during the 2004 and 2005 seasons.

[2] Though he recovered from his arm injury, his season was effectively brought to an end on April 19, 2008, when he was involved in a heavy crash with Robertino Pietri during qualifying at Barber Motorsports Park.

[4] Hayden's left pinky finger was eventually amputated after specialists determined that the digit could not be repaired.

Hayden also contested the Moto2 race at the Indianapolis Grand Prix, riding a Moriwaki run by former World Champion Kevin Schwantz.