It's the second consecutive win for the Chip Ganassi Racing team, which won the Twelve Hours of Sebring last month in a Ford with Marino Franchitti in the lineup.
It's the 58th career victory for Pruett and 29th for Rojas. All of Rojas' victories are with Pruett.
Ricky Taylor and Jordan Taylor finished second for Wayne Taylor Racing in a Chevrolet. Joao Barbosa and Christian Fittipaldi finished third.
Jan Magnussen and Antonio Garcia teamed to win the GTLM class. They are the defending American Le Mans Series GT champions, and Saturday's win was the first for the new Corvette C7.R.