But how long will it stay there?
The Yankees are back in first-place in the division for the second time in three days after Friday's 8-5 win but the series is far from over. The Orioles are not going anywhere, especially when you consider they trail the Yankees by only one game.
"It starts with the little things," Yankees third baseman Alex Rodriguez said. "Obviously, we've talked about the DNA of the team and all that -- and home runs are good. But it starts with good at-bats. It adds up."
The lead in the National League West is starting to add up for the Giants. San Francisco extended its lead over the Dodgers to 5 1/2 games in the division following the 5-2 victory in the first game of the series on Friday. Matt Cain is scheduled to take the hill against Dodgers starter Chris Capuano in the second game of the series.
"It's always good to get the first one, and there's a lot of attention on these games," Giants manager Bruce Bochy said. "It's pretty intense out there, and really both teams played well, and it's always good to get the first one, no getting around that. Now we have to be ready to go [Saturday]."
In the AL West, the A's cut into the Rangers' division with a 6-1 victory against the Mariners to shrink the deficit to 4 1/2 games. Meanwhile, Ben Zobrist's two-run home run in the bottom of the 11th inning propelled the Rays to a 3-1 victory over Texas. The Rays now trail the first-place Yankees by only two games in the division.
"It was a pitchers' duel out there all night," Rangers manager Ron Washington said. "[The Rays] got the last blow. You never want to lose. It was a real good game. They had the last opportunity out and they got it done."
The Braves have scored two earned runs over their past 32 innings but they still have won five of their past six games because of their strong pitching. Including Friday's 3-0 win against the Mets, the Braves have thrown three consecutive shutouts.
The Braves, winners of three in a row, made up ground in the division following Washington's 9-7 loss to the Marlins.
The Cardinals came up short against the Brewers in extra innings on Friday but still remain in the second NL Wild Card spot.
Today's key games to watch (all times ET)
Royals (Chen, 4-11) at White Sox (Sale, 15-6), 4:05 p.m. Preview >
The White Sox have a one-game lead over the Tigers in the AL Central but cannot overlook the Royals this weekend.
Marlins (Buehrle, 12-12) at Nationals (Detwiler, 9-6), 1:05 p.m. Preview >
Detwiler's role is about to get more prominent, with Stephen Strasburg scheduled to make only one more start before the club shuts him down for the season.
Yankees (Sabathia, 13-4) at Orioles (Saunders, 7-11), 7:05 p.m. Preview >
The Yankees hold a one-game edge in the AL East standings after a split in the first two tilts of the four-game set.
Braves (Medlen, 7-1) at Mets (Hefner, 2-5), 4:05 p.m. Preview >
The Braves have won five of six and lead the National League Wild Card race. Medlen has a 0.54 ERA in seven starts.
Dodgers (Capuano, 11-10) at Giants (Cain, 13-5), 4:05 p.m. Preview >
The Giants lead the Dodgers by 5 1/2 games in the NL West and are riding a four-game winning streak against their Los Angeles rivals.
Rangers (Darvish, 14-9) at Rays (Archer, 0-2), 7:10 p.m. Preview >
Darvish flirted with a perfect game in his last outing and the Rangers could use another solid start. They lead the A's by 4 1/2 games in the AL West. Rays trail the Yankees by only two games in the AL East.
Cubs (Samardzija, 8-13) at Pirates (McDonald, 12-7), 7:05 p.m. Preview >
Samardzija is making his final start of the season and Pirates are trying to make up ground in the NL Wild Card race.
Tigers (Verlander, 13-7) at Angels (Wilson, 11-9), 9:05 p.m. Preview >
Get ready for a showdown when two of the best pitchers in the American League take the hill with playoff implications on the line.
Astros (Norris, 5-11) at Reds (Arroyo, 11-7), 7:10 p.m. Preview >
Arroyo has allowed just 11 hits over his last 20 innings and has a 2.25 ERA in his last three starts.
A's (Anderson, 3-0) at Mariners (Iwakuma, 6-3), 9:10 p.m. Preview >
The streaking Athletics have won seven of their last 10 games and trail the Rangers by only 4 1/2 games in the AL West.
Brewers (Fiers, 8-7) at Cardinals (Westbrook, 13-10), 7:15 p.m. Preview >
The Cardinals are in the mix for the NL Wild Card and could use a solid outing from their starter Saturday. Westbrook has allowed 14 runs and 27 hits in 15 1/3 innings.
If the postseason started today ...
Wild Card: A's at Orioles
Division Series: Yankees at White Sox | Rangers at Wild Card winner
Wild Card: Cardinals at Braves
Division Series: Reds at Giants | Nationals at Wild Card winner
To calculate a team's magic number, take the number of games it has remaining on the schedule and add one. Then subtract the difference in the loss column between the team and its closest pursuer.
Tie-breaker games will be played to determine the division winner, even if the two tied clubs are assured of participating in the postseason. If a division championship tie-breaker game is necessary, the head-to-head record between the tied clubs will determine home-field advantage. If the head-to-head record is tied, then division record will be the next tie-breaker.
If two clubs are tied for both Wild Card berths, home-field advantage will be determined by the head-to-head record between the tied Clubs. If the head-to-head record is tied, then division record will be the next tie-breaker.
2012 Postseason Schedule
Wild Card playoff games: Oct. 5
Division Series: Oct. 6-12
American League Championship Series: Oct. 13-21
National League Championship Series: Oct. 14-22
World Series: Oct. 24-Nov. 1