The Red Sox, who on Tuesday became the first team this season to clinch a playoff berth, reached the century mark in their 146th game. The 2001 Seattle Mariners reached 100 wins in their 140th game and went on to win a major-league-record 116 games.
Boston has reached 100 wins just four times in team history, last doing so when Ted Williams returned from World War II in the 1946 season. They went 104-50 that year and then lost to the St. Louis Cardinals in a seven-game World Series.
The Red Sox won the World Series the other two times they won 100 games -- in 1915 (101-50) and 1912 (105-47).
Boston's previous 100-win team featured Williams, Johnny Pesky, Bobby Doerr and Dom DiMaggio.
This year's Red Sox need only to go 6-10 the rest of the way to break the franchise record of 105 wins, set in 1912.
"Somebody just told me it's been done three times here and the last one was 70-something years ago,'' first baseman Mitch Moreland said. "I think that speaks for itself.''
Alex Cora is the first manager with 100 wins in his first season with a club since Felipe Alou accomplished the feat with the 2003 San Francisco Giants and the first in his initial season as a big league manager since Dusty Baker with the 1993 Giants.
"Don't get me wrong; 100 is 100. But we've got bigger goals, obviously,'' Red Sox manager Alex Cora said. "Today we got closer to one of those goals.''
Should the Red Sox go at least 10-6 the rest of the way, Cora would pass Ralph Houk (1961 New York Yankees) for the most wins by a rookie manager in MLB history.
Boston, which scored its only run Wednesday on a wild pitch, saw its magic number for clinching the AL East drop to seven over the second-place Yankees.
The Associated Press and ESPN Stats & Information contributed to this report.