Neal Huntington is hired as General Manager of the Pittsburgh Pirates. He replaces Dave Littlefield.

Brewers first baseman Prince Fielder becomes the youngest major leaguer to hit 50 home runs in a season, going deep twice in the team’s 9-1 victory over the Cardinals at Miller Park. The 23 year-old cleanup hitter and his father, Cecil, who hit 51 round-trippers with the Tigers in 1990 are the first father-and-son tandem to accomplished the feat.

Baltimore completes a season sweep of the Royals with a 3-2 victory at Camden Yards. The Orioles, twenty-three games under the .500 mark, beat Kansas City seven times in seven tries, making it only the sixth time in team history that a season series has been swept from an AL opponent.

Milton Bradley’s anterior cruciate ligament is torn when his manager Bud Black spins him to the ground to keep him from going after umpire Mike Winters in the eighth inning of a 7-3 loss to the Rockies. The Padres’ left fielder will miss the rest of the season due to the injury, and the first base ump will be suspended for the remainder of the season without pay for his actions during the confrontation.

In front of the largest crowd of the season, the Nationals, in the last major league game to be played at RFK, beat Philadelphia, 5-3, to finish their three-year stay at the 41 year-old Washington, D.C. stadium with a home win-loss record of 122-121. The ballpark, which also hosted the expansion Senators and the NFL’s Redskins, has served as the Nats’ home since 2005, when the franchise shifted from Montreal to the District of Columbia.

Mike Mussina becomes the 45th pitcher in major league history to win 250 games when the Yankees beat the Blue Jays in the Bronx, 7-5. ‘Moose’ insists that the game ball go to Joba Chamberlain, the rookie phenom who picks up his first career save.

At Petco Park, the Rockies beat the Padres, 7-3, for their 84th win of the season to break a club record. Jeff Francis, who gives up seven hits and two runs in his eight innings of work, ties Kevin Ritz (1996) and Pedro Astacio (1999) for club victories and establishes a new franchise mark for left-handers, winning his 17th game of the campaign.

2007 – Lance Berkman hits a home run for the 7th straight September 21st. This is a record for a single date; Lou Gehrig had homered on June 8 six years in a row.