Danieal Manning and Kareem Jackson returned interceptions for touchdowns, and Matt Schaub threw two TD passes in Houston's 38-14 win over the Tennessee Titans on Sunday.
Arian Foster also had a touchdown run for Houston (4-0). Even though the Texans were outgained 325-297 by the Titans (1-3), they broke open a close game after halftime.
"We really played great defense, the whole second half," Kubiak said. "The defensive play in the second was what got us going, the big play."
Houston's offense ranked among the NFL's top-5 from 2007-11, but the team didn't win its first division title until after Wade Phillips became the defensive coordinator before last season.
The Texans ranked second in total defense coming into Sunday's game, and came out hitting.
Titans quarterback Jake Locker left in the first quarter and didn't return after hurting his left, non-throwing shoulder on a hit by Glover Quin. Locker hurt the same shoulder in the season opener against New England.
Matt Hasselbeck threw two touchdown passes in relief of Locker. Tennessee coach Mike Munchak said Locker was "sore" and would undergo an MRI exam Monday.
Chris Johnson carried 25 times for 141 yards, more than tripling his rushing total through the first three games.
"It was a pretty good game," Johnson said. "We ran the ball. I felt like my offensive line went out there and did a great job from the first snap, just getting up on guys, pushing those guys back, and just giving me somewhere to run."
The Texans led 14-7 at halftime, but their offense bogged down for a while after that. Houston mustered only two first downs in the second quarter, and went three-and-out on the first series of the third quarter.
Leave it to Houston's defense to get the Texans going again.
Hasselbeck threw behind tight end Taylor Thompson, and the ball ricocheted to Manning, who weaved 55 yards for a touchdown. Manning's play not only reignited the restless fans at Reliant Stadium, it also seemed to wake up the offense.
"It's a nice luxury to have, when you see them make those turnovers," Schaub said. "It creates such a lift for us."
The Texans went without a huddle and breezed down the field in just over two minutes. Foster broke a 16-yard run, and Schaub threw a 28-yard touchdown pass to tight end Owen Daniels.
Down 28-7, the Titans were forced to throw more despite Johnson's best game of the season. Johnson came in with only 45 yards rushing on 33 carries through the first three games.
Hasselbeck fumbled when he was hit by Antonio Smith in the fourth quarter, and J.J. Watt recovered at the Tennessee 24. Shayne Graham kicked a 33-yard field goal with 5:38 left.
Tennessee crossed midfield, and Jackson intercepted Hasselbeck and raced untouched to the end zone, high-stepping the last 10 yards.
Hasselbeck threw a short TD pass to Wright in the final minute. He finished 17 of 25 for 193 yards.
"It's frustrating because I feel like we're not that far away," Hasselbeck said. "But we didn't play great and we had turnovers and I was a part of three of them. It's just frustrating because I know we're capable of a lot more."
The Texans led 7-0 when Locker was hurt on the Titans' second series. On third down, Quin blitzed and plowed into Locker for his first career sack. Locker immediately grabbed his left hand and arm as he was down on the turf. He walked to the locker room on his own, and later returned in street clothes, his left arm in a sling.
Houston took over near midfield and converted a fourth-and-1 from the Tennessee 38. Foster scored on a 4-yard run.
Hasselbeck, in his first action since the opener, threw a 25-yard pass to tight end Jared Cook. The Texans smothered Johnson for a 6-yard loss to force another punt for Tennessee.
Johnson later broke a 19-yard run and the Titans' offense showed some life with Hasselbeck taking the snaps. Hasselbeck found fullback Craig Stevens for a 19-yard touchdown with 7:52 left in the first half.
Johnson limped off the field late in the first half, after he was tackled by linebackers Brian Cushing and Connor Barwin. He returned for the Titans' first series of the third quarter.
Notes: Watt has 7 1/2 sacks this season. ... The Texans topped 30 points for the third time in four games. ... Graham reached 1,000 career points. ... Texans RG Antoine Caldwell left in the second quarter with a sprained right ankle. ... Titans LB Patrick Bailey, a special-teams player, injured his left hand and stayed in the game. Munchak said he would be re-evaluated on Monday. ... Johnson earned his 29th career 100-yard game.
Catch all the highlights from today's game and an in-depth analysis from our own Bob Slovak and Spencer Tillman tonight on "Inside the Game" at 10:35pm.