On October 16, Lewis started Game 2 of the 2010 American League Championship Series at home against the New York Yankees. Lewis went 5.2 innings and gave up 2 earned runs on 6 hits. However, he earned the decision, and became the first Ranger pitcher to win a post-season home game in franchise history. On October 22, Lewis started Game 6 of the American League Championship Series, also at home, against the New York Yankees. He pitched 8 innings, allowing 1 run on 3 hits, aiding the Rangers to a decisive 6–1 victory. The win allowed the Rangers to win the Series and earn their first-ever American League Pennant. On October 30, Lewis started game 3 of the 2010 World Series, at home against the San Francisco Giants. Lewis went 7 innings, allowing 2 earned runs on 5 hits, and earned the win which was the first Rangers victory in a World Series game (and first World Series win for an MLB team in the state of Texas, as the Houston Astros were swept in the 2005 World Series). After winning those two crucial home playoff games in the 2010 ALCS and Game 3 of the 2010 World Series, Lewis was, so far, the only Rangers pitcher accredited towards three of the Rangers home playoff wins as no other Rangers pitcher had even one. The Rangers went on to lose the World Series in five games to the Giants.