The 6-foot-5, 288-pound rookie defensive end is constantly swatting passes, and even intercepting a few. He finally hung onto one when it counted, in the biggest game of the year.
Watt's game-changing interception return for a touchdown on Saturday propelled the Texans (11-6) to a 31-10 win over Cincinnati and set up a matchup with Baltimore (12-4) in the next round of the playoffs.
"That was a huge momentum lift for us," linebacker DeMeco Ryans said. "When J.J. got the touchdown, the confidence level rolls, everyone is excited and we continued to feed off that. J.J. provided for us that huge play that just catapulted us to take it to the next level."
They'll be underdogs, but history is actually on their side.
The Texans are one of six teams to join the NFL since the merger with the AFL in 1970. All six won their postseason debut, and the previous five (Carolina, Jacksonville, Tampa Bay, Baltimore and Seattle) all went on to reach the championship game in their respective conference. The Ravens won the Super Bowl after the 2000 season.
"We made history," Watt said. "We're excited about another chance to make history up there in Baltimore."
Then Watt, the Texans' first-round draft pick and a cornerstone of the rebuilt defense, leaped to snag Andy Dalton's pass and chugged 29 yards for a touchdown, sending the record crowd of 71,725 into a frenzy.
The Texans dominated the second half, with Andre Johnson catching a 40-yard touchdown pass from rookie T.J. Yates and Arian Foster punctuating the victory with a signature 42-yard TD run, tiptoeing down the sideline and easily pushing away Bengals safety Chris Crocker.
Yates looked as poised and sharp as he has in weeks, though he only completed 11 passes for 159 yards. And Johnson finally seemed like himself again, after missing nine games in this historic season with hamstring injuries.
"I'm just glad the hamstrings didn't talk to me," Johnson said.
Drafted in the first round of 2003 out of Miami, Johnson is the lone holdover from the middling stretch before coach Gary Kubiak took over, when the Texans mostly languished at the bottom of the AFC South, a favorite opponent for Peyton Manning and the Colts.
Johnson savored his shining moment on Saturday, then immediately started looking ahead to the next one.
"I can remember when I was a rookie like it was yesterday," Johnson said. "It has been nine seasons, and it has gone by really fast. The college days were fun, and I was able to play in a couple of big games. But all I am thinking about is what is next for this organization.
"So we go to Baltimore next week, and we are going to try to go up there and do what we did (Saturday)."
Johnson missed the previous meeting with the Ravens with a right hamstring injury that required minor surgery. It was also the Texans' first game after star outside linebacker Mario Williams tore a chest muscle.
"They have been an excellent team all year long," Kubiak said of the Ravens. "You have to go play at their place. So we understand. We went there earlier in the season, and we'll have to play as good as we can possibly play."
The Texans said after Saturday's game that their late-season swoon actually benefitted them, because it reset everyone's focus. Suddenly, the team's confidence is restored and a return trip to Baltimore doesn't seem so intimidating.
"We've been there before, and it's not going to be anything new," linebacker Brian Cushing said. "I'm sure it'll be a bit louder, with the playoff environment. They'll be excited, coming off a bye. But we'll be ready. Going up there, it's going to be a fun, exciting challenge. We're ready for it."