Jonathan Tyler Lester is an American former professional baseball pitcher. He played in Major League Baseball (MLB) for the Boston Red Sox, Oakland Athletics, Chicago Cubs, Washington Nationals, and St. Louis Cardinals. Less than two years after being diagnosed with lymphoma, Lester started and won the final game of the 2007 World Series for the Red Sox and, in May 2008, pitched a no-hitter against the Kansas City Royals. He helped lead the Red Sox to another championship in 2013, and he won the 2016 World Series with the Cubs. Lester started the opening game of a playoff series 12 times, which was a record for the most in baseball history until Justin Verlander passed him in 2023.

The 2007 World Series was the championship series of Major League Baseball's (MLB) 2007 season. The 103rd edition of the World Series, it was a best-of-seven playoff between the National League (NL) champion Colorado Rockies and the American League (AL) champion Boston Red Sox; the Red Sox swept the Rockies in four games. It was the Rockies' only appearance in a World Series. The Red Sox's victory was their second World Series championship in four seasons and their seventh overall; it also marked the third sweep in four years by the AL champions. The series began on Wednesday, October 24 and ended on Sunday, October 28.