The Halos are 3 1/2 games behind the Orioles for the second AL Wild Card spot and 4 1/2 behind the A's for the first spot.
"If we can finish the way we've been playing the last couple of games, we'll have a lot better chance to get where we want to go," said Angels starter C.J. Wilson, who earned the win.
The AL East race became even tighter when the Yankees dropped a 4-3 decision to the Rays at Tropicana Field, allowing the Orioles, with their 4-0 win over the Blue Jays, to move within a game of the division lead. The win also put Tampa Bay just 1 1/2 games back in the Wild Card and 2 1/2 behind in the division.
"It's not a good feeling," Yankees second baseman Robinson Cano said. "You lose some games, and you just want to win games. You don't want to put your head down. We've just got to turn the page; just be ready for tomorrow."
In the AL Central, the White Sox reclaimed sole possession of first place as they beat the Twins, 4-2, and the Tigers lost to the Indians, 3-2.
Meanwhile, in the National League, Washington earned its 82nd win of the season with a 2-1 defeat of the Cubs, keeping its lead in the East at 6 1/2 games over Atlanta. It was a milestone win for the Nationals, who set a record for most wins since they arrived from Montreal in 2005.
The Giants kept their 4 1/2-game lead over the Dodgers in the NL West with their 9-8 win over the D-backs in 10 innings. Los Angeles also earned a victory in extras, squeaking out a 4-3 win over the Padres in 11 innings. The win moved the Dodgers to a half-game behind the second NL Wild Card spot.
The Braves picked up a 6-1 win over the Rockies to stay atop the NL Wild Card standings, and the Cardinals won, 5-4, over the Mets to keep the second NL Wild Card spot.
Today's key games to watch (all times ET)
Indians (Justin Masterson, 10-12) at Tigers (Rick Porcello, 9-10), 7:05 p.m. Preview >
The Tigers will try to bounce back from their loss to the Indians as they fight with the White Sox for the top spot in the AL Central.
Astros (Jordan Lyles, 3-10) at Pirates (Wandy Rodriguez, 9-13), 7:05 p.m. Preview >
The Pirates are 2 1/2 games behind the Cardinals for the second NL Wild Card spot after dropping four straight. They'll look to get a strong effort from Rodriguez against his former club.
Orioles (Zach Britton, 4-1) at Blue Jays (Carlos Villanueva, 7-4), 7:07 p.m. Preview >
The Orioles can move into a first-place tie with a win and a Yankees loss to the Rays.
Rockies (Drew Pomeranz, 1-8) at Braves (Tommy Hanson, 12-7), 7:10 p.m. Preview >
The Braves, holding on to the first NL Wild Card spot, will look to Hanson after their 6-1 win on Monday.
Yankees (Freddy Garcia, 7-5) at Rays (Alex Cobb, 8-8), 7:10 p.m. Preview >
The Yankees, struggling to score runs, will try to get an important win and increase their division lead against the pesky Rays.
Twins (Scott Diamond, 10-6) at White Sox (Jose Quintana, 5-3), 8:10 p.m. Preview >
Chicago got a much-needed win over the Twins on Monday to regain sole possession of first place in the AL Central. On Tuesday they hand the ball to Quintana.
Rangers (Matt Harrison, 15-8) at Royals (Jeremy Guthrie, 6-12), 8:10 p.m. Preview >
Harrison will look to increase the Rangers' lead over the A's in the AL West as he goes for his third straight win. The left-hander is 10-4 with a 3.05 ERA in 15 road starts, compared with a 5-4 record and 3.68 ERA in 11 home starts.
Mets (Matt Harvey, 3-3) at Cardinals (Jaime Garcia, 3-6), 8:15 p.m. Preview >
Just ahead of the Dodgers for the second NL Wild Card spot, the Cardinals will send Garcia to hill as he tries to snap a personal two-game losing streak.
Angels (Zack Greinke, 12-5) at A's (Jarrod Parker, 9-7), 10:05 p.m. Preview >
The Angels snapped Oakland's nine-game winning streak on Monday and will look for another important win as they try to climb their way back into serious playoff contention. They are 3 1/2 games behind the second AL Wild Card spot.
Padres (Eric Stults, 5-2) at Dodgers (Clayton Kershaw, 12-8), 10:10 p.m. Preview >
The Dodgers will try to make a dent in the Giants' 4 1/2-game lead in the NL West behind Kershaw, their ace.
D-backs (Ian Kennedy, 12-11) at Giants (Ryan Vogelsong, 12-7), 10:15 p.m. Preview >
The Giants have won 13 of their past 17 games and have a 4 1/2-game lead over the Dodgers in the NL West.
To calculate a team's magic number, take the number of games it has remaining and add one. Then subtract the difference in the loss column between that team and its closest pursuer.
A tiebreaker games 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 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 division record will be the next tiebreaker.
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