The 6-foot-5 defensive end fought off a blocker, leaped in front of Dalton's pass and returned it 29 yards for a touchdown. It gave Houston the lead just before halftime, and the Texans never looked back in a 31-10 victory in the AFC wild-card game Saturday.
"He jumped up and made a play," Dalton said. "It was a great job on his part."
Watt, also a rookie, works on plays like that in practice, but had never had an interception. And this one helped the Texans to the first playoff win in franchise history.
"I was really just trying to put my hands up and get in the way of the passing lane," Watt said. "It happened to kind of stick. I realized I had the ball, so I just ran to the end zone just trying not to fall down."
The Bengals were making their third playoff appearance in seven seasons, but haven't won since 1991, when they beat the Houston Oilers 41-14.
Chris Crocker dropped an interception on a drive by Houston in the third quarter. A dejected Crocker sat at his locker with his head down for a long time after the game.
"It was a touchdown if I would have caught it," Crocker said. "They made those big plays and we didn't and that's why they're moving on."
"I've got to make that play," Jones said. "It's a tough one, but I'm not going to beat myself up too much over it. All I can do is learn from this experience."
The Bengals had trouble containing Johnson, who was at full speed for the first time since injuring his left hamstring Dec. 4 and finished with 90 yards receiving.
Dalton had thrown just one interception in the past six games, but was intercepted three times on Saturday. The second came when he threw a long pass under heavy pressure which was intercepted on fourth down by former Bengal Johnathan Joseph.
Danieal Manning, signed along with Joseph to shore up Houston's secondary in the offseason, grabbed the third one midway through the fourth quarter.
Dalton, who grew up in the Houston suburb of Katy and played in college at TCU, was sacked a season-high four times and tied a season-high with three interceptions while dealing with the rowdy, record crowd of 71,725.
Cincinnati couldn't get anything going on the ground against fourth-ranked rush defense and Cedric Benson finished with just 14 yards rushing.
Green had four receptions for 42 yards in the first half, but added just one catch for five yards after that.
"They made some great adjustments coming out of halftime," said Green, who had 1,104 yards receiving this season.
The Texans tied it at 10 less than two minutes before halftime on a 39-yard field goal by Neil Rackers. Johnson had a 17-yard catch on third down to keep that drive going, but couldn't grab a throw from Yates in the end zone to force the field goal.
They eventually settled for a 37-yard field goal by Nugent to go up 10-7 midway through the second quarter.
Benson bulled into the end zone four plays later for a 1-yard touchdown to give Cincinnati a 7-0 lead.
Foster took it from there with three straight runs capped by an 8-yard touchdown run where he cut to the outside for the score to make it 7-7 with about five minutes left in the first quarter.
Notes: Former President George H.W. Bush and his wife Barbara attended the game and watched the game from a suite with NFL commissioner Roger Goodell. ... Goodell was on the field before the game shaking hand and posing for pictures with fans. ... Lewis challenged two plays in the first half and lost both, leaving him without any for the second half.