To begin the 2008 season, her second with Andretti Green Racing, Patrick scored her then best career Homestead finish of sixth. She followed that up with another top ten by scoring a tenth-place finish at St. Petersburg. At the Indy Japan 300 at Twin Ring Motegi on April 20, Patrick moved to the front of the field with three laps remaining after the previous leaders were forced to make pit stops for fuel and held the first position to secure her maiden IndyCar victory. This made her the first woman to win a top-level sanctioned open wheel car racing event. At the season's fourth round at Kansas Speedway, Patrick finished 19th after a hubcap failure. After qualifying fifth for the Indianapolis 500, she retired from the race early after a collision with Ryan Briscoe in the pit lane. Thereafter, Patrick finished within the top ten for five of the next six races in the season. At Mid-Ohio Sports Car Course, an incident with Milka Duno in practice turned into a confrontation before walking away. She ended the season with three further top-ten finishes with a best of fifth at Infineon Raceway. Patrick finished sixth in the final standings with 379 points, the highest placed American over the course of the season.