The World Series television rating on Fox was up 17 percent over last year but was the lowest for a matchup that went at least six games.
Boston's 4-2 Series win over St. Louis averaged an 8.9 rating, 15 share and 14.9 million viewers, Nielsen Media Research said Thursday.
San Francisco's four-game sweep of Detroit last year averaged a record-low 7.6/12 and was seen by 12.7 million viewers. That was among only three Series that had lower ratings than this year's, joined by 8.4 ratings for Philadelphia's five-game win over Tampa Bay in 2008 and San Francisco's five-game victory over Texas in 2010.
Boston's 6-1 victory in Wednesday night's clincher received an 11.3/18 and was seen by 19.2 million viewers, baseball's highest rating since Game 7 of the 2011 World Series.
The game, which marked the first title won by the Red Sox at Fenway Park since 1918, drew a 55.2/75 in Boston, the highest MLB rating there since Game 4 of the 2007 World Series. The Boston rating peaked at a 59.5/84 from 11-11:30 p.m., which included the final out and the start of the postgame celebration.
"This baseball season has been a tremendous success across the board for FOX Sports, and 2014 can't get here soon enough," Fox Sports President Eric Shanks said in a statement. "Our postseason coverage saw a 26 percent jump year to year, while ratings for the All-Star game grew and several of our regional sports networks had record-setting seasons."