In 2008, Billingsley elevated to one of the top pitchers in the National League while demonstrating his potential as an ace. He finished the year with a 16–10 record, was 5th in the NL (and 9th in the majors) with 201 strikeouts, and recorded an ERA of 3.14 and a WHIP of 1.34 in 200.2 innings pitched. Billingsley pitched his first career complete game shutout against the San Francisco Giants on July 30, 2008, allowing five hits and recording eight strikeouts without allowing a walk. On September 6, Billingsley faced Arizona ace Brandon Webb and helped to hold him off long enough for a Manny Ramirez homer, and a 7–2 win, his 14th of the season.