INDIANAPOLIS — Peyton Manning spent one half deciphering the Houston defense.

He spent the final two quarters cutting it up.

The two-time league MVP led Indianapolis on four straight scoring drives in the second half, wiping out two Houston leads and giving the Colts a badly needed 33-27 victory today.

Indy (6-4) won its third straight, a season-best, as it stayed near the top of the muddled mass battling for the AFC's two wild-card spots.

For Manning, it seemed like old times. He took advantage of every opportunity, finished 30-of-46 for 320 yards with two touchdowns and magnificently mixed the run and pass in the second half when Houston (3-7) couldn't keep up with the Colts.

The script looked familiar, too.

Joseph Addai ran for 105 yards and one TD, his first 100-yard day since November 2007. Marvin Harrison caught nine passes for 77 yards and another score and Indy produced a season-high 474 yards in offense.

Houston's defense was flummoxed as it wasted Steve Slaton's big day. Slaton ran 14 times for 156 yards, a franchise record for a rookie, and scored on a 71-yard run, the longest in team history. But the Texans still lost their third straight.

Manning was just too good.

He masterfully led the Colts on touchdown drives of 81, 80 and 73 yards in the second half, erasing Houston's 13-9 halftime lead and the Texans' 20-16 advantage after Slaton's long TD run.

And when he had to run out the clock, Manning nearly did that, too.

Manning opened the second half with a 23-yard scoring pass to Addai, the back's first TD reception of the season, to give Indy a 16-13 lead.

Three plays later, Slaton hit a hole in the middle of the line at full speed, evaded Melvin Bullitt's tackle in the secondary and outran two Indy defenders for his 71-yard run to put Houston back on top. Bullitt started in place of the injured Bob Sanders.

Manning took care of that quickly.

He gashed Houston's defense for three completions of at least 11 yards, then handed the ball to Addai for a 7-yard TD run that put Indy ahead 23-20 midway through the third quarter.

The next time Indy got the ball, Manning threw a 10-yard TD pass to Harrison, who wrestled the ball away from DeMarcus Faggins on his inside shoulder and fell into the end zone for a 30-20 lead.

Houston closed to 30-27 when Ahman Green scored on a 2-yard TD run with 8:54 to go, but Manning virtually sealed it with a drive that consumed 7:02. It led to Adam Vinatieri's fourth field goal of the game, a 31-yarder that made it 33-27.

Sage Rosenfels, who replaced the injured Matt Schaub, was picked off by Bullitt with 38 seconds left to end Houston's comeback hopes.