Manning promised the Texans defense would "get its swag back" following a disappointing conclusion to the regular season.
The defense played a major role in the Texans' 19-13 wild-card win over the Bengals on Saturday. Running back Arian Foster took care of the rest.
Houston moves on to face the second-seeded Patriots in next Sunday's divisional round.
"When you get into the playoffs, you win to stay in," said Manning, a former Bear. "It's a great feeling. We did what we were supposed to do."
The Texans forced the Bengals to go 0-for-9 on third down while surrendering just 198 total yards. Cornerback Johnathan Joseph put the clamps on A.J. Green for the most part, limiting one of the league's most dangerous threats to five catches (80 yards) on 11 targets. Joseph also intercepted Andy Dalton.
Defensive player of the year front-runner J.J. Watt had a sack, two tackles for losses, two quarterback hits, and two pass deflections.
Texans defensive coordinator Wade Phillips remained expressionless in the locker room after the game, but one could tell he was bubbling with joy inside.
"We were down to our fourth inside backer, but our guys came in, stepped up and played well," Phillips said. "I was pleased that (the Bengals) didn't get a touchdown on us defensively. A big key for us was to try to stop a team that was on a roll."
Not to be outdone was Foster, who became the first player in NFL history to go for 100 rushing yards in each of his first three playoff games. Foster finished with 140 yards on 32 carries with a touchdown. He opened up timely play-action opportunities for quarterback Matt Schaub, who completed 29 of 38 passes for 262 yards.
Foster was quick to credit his offensive line.
"We controlled the line of scrimmage," he said. "Anytime we do that, it's hard to beat us."
The Bengals still had a chance in the waning moments. Dalton took the ball from his own 20 with 6 minutes, 15 seconds left and drove the offense to the Texans' 36. He was helped by a 15-yard pass interference penalty on Texans safety Shiloh Keo.
But on third-and-11, Dalton missed a streaking Green, who had a step on both Joseph and Manning. Then on fourth down, Dalton threw a short pass to Marvin Jones, who was stopped by Joseph and Keo 3 yards shy of the first down.
The Texans took over and sealed the game when Schaub found tight end Garrett Graham for 7 yards on third-and-2 from his own 36. Graham secured the ball despite absorbing a vicious hit. It allowed the Texans to run out the clock.
"They were all up in there thinking we were going to run the ball, rightfully so," Schaub said of the game-clinching play. "(Graham) made a huge play and took a lick for it."
Schaub gave up a pick-six to Bengals cornerback Leon Hall, but he shook off the blunder and managed the game. Kicker Shayne Graham helped the cause with four field goals.
But the Texans knew they could have played even better. In the locker room, Foster offered a few words of encouragement to Keo for the nearly costly pass interference penalty by saying, "If you played the ball on that, you're on 'Sports Center.' ''
The Texans might need a few highlight plays to beat the Patriots next weekend.