ST. LOUIS -- The Nationals didn't put themselves in a better position to clinch the National League East on Friday night, but they left Busch Stadium after a 12-2 loss with a division title as close as ever.

"We got a little help from our friends," Nationals manager Davey Johnson said. "That was nice."

Washington suffered its most lopsided defeat of the season at the hands of St. Louis, which roughed up starter Edwin Jackson for nine runs in 1 1/3 innings, but the Nationals' magic number dropped to two because the second-place Braves dropped a 3-1 decision to the Mets at Turner Field.

The Nationals can officially claim their first NL East championship as early as Saturday if they beat the Cardinals and the Braves lose again.

"That was a beating, there. But we're obviously watching the scoreboard," first baseman Adam LaRoche said. "The Braves finally lost a game this month, so I guess we can take that as a positive."

Saturday's key games to watch (all times ET)

Nationals (Zimmermann, 12-8) at Cardinals (Lohse, 16-3), 7:15 p.m. Preview >

Mets (Young, 4-8) at Braves (Minor, 10-10), 7:10 p.m. Preview >

If the postseason started today ...

This is how the teams would match up: Postseason Bracket »

Postseason 101

Magic numbers
To calculate a team's magic number, take the number of games it has remaining and add one. Then subtract the difference in the number of losses between that team and its closest pursuer.

Tiebreaker scenarios
A tiebreaker game will be played to determine a division winner, even if the tied clubs are assured of participating in the postseason. If a division championship tiebreaker is necessary, the head-to-head record between the clubs will determine home-field advantage. If the head-to-head record is tied, then the division record will be the next tiebreaker.

If two clubs are tied for the two Wild Card berths, home-field advantage will be determined by the head-to-head record between the clubs. If the head-to-head record is tied, then the division record will be the next tiebreaker.

Tiebreaker rules »

2012 postseason schedule
Wild Card playoff games: Oct. 5
Division Series: Oct. 6-12
AL Championship Series: Oct. 13-21
NL Championship Series: Oct. 14-22
World Series: Oct. 24-Nov. 1