HOUSTON – Tom Savage’s run as the starting quarterback for the Houston Texans this season might have lasted only two quarters.

In the end, however, a mid-game switch wasn’t enough.

Though Houston’s offense improved after head coach Bill O’Brien pulled Savage and inserted rookie Deshaun Watson at the start of the second half on Sunday, the team still lost its regular-season opener against the Jacksonville Jaguars, 29-7.

The question, now, becomes whether the switch turns out to be permanent.

Under Savage, Houston’s offense gained only 52 total yards on 28 offensive plays and did not score.

Under Watson, the Texans amassed 151 total yards on 41 plays and put up just seven points.

Watson completed 12 of 23 passes for 102 yards, one touchdowns and one interception. He also lost a fumble on a strip sack.The upset is a setback in the AFC South for the Texans, who are looking to repeat as the division winner.

Photos: Texans host Jags in season-opener at NRG

Jaguars quarterback Blake Bortles played well enough, completing 11 of 21 attempts for 125 yards and one touchdown. Rookie running back Leonard Fournette posted a solid debut, rushing for 100 yards on 26 carries and added a score.

Watson threw a 4-yard touchdown to wide receiver DeAndre Hopkins on his first drive to cap a 14-play, 75-yard scoring march. But on the ensuing series, he lost a fumble after a strip sack by Jaguars defensive end Dante Fowler. His interception came in the fourth quarter and was forced into triple coverage.

Savage completed just seven of 13 attempts for 62 yards. He often held on to the ball far too long and, despite shaky play from the Houston offensive line, was sacked six times.

Perhaps the most important improvement Watson showed over Savage was mobility.

Houston’s play calls helped get Watson on the move and out of the pocket, where he gave the Texans’ offense a different element and allowed receivers to buy extra time to get open.

Still, Houston’s offensive line did not protect Watson well, either, as the rookie was sacked four times.

The Texans traded up 13 spots to select Watson with the No. 12 overall selection in April's draft. Prior to the start of the season, O’Brien had been adamant that Savage would be the team’s starter after he took the job last season from Brock Osweiler, whom the team traded this offseason.

The loss came on an emotional day for the Texans, who honored first responders during Hurricane Harvey and subsequent relief efforts prior to kickoff. The responders were involved as Texas flag holders, the Color Guard, “Homefield Advantage captains” and coin toss captains.

A moment of silence was held for victims. As the Texans defense was introduced before the game, each player sprinted out onto the field with either an American or Texas state flag.

Defensive end J.J. Watt, who drew the largest response from the crowd, wore cleats with the design of the state flag.Watt’s Houston Flood Relief Fund started with a goal of $200,000 and surpassed $31 million as of kickoff.

The Texans face the Cincinnati Bengals on Thursday night. The Jaguars, who will stay in Houston and assess their travel options Monday depending on the outcome of Hurricane Irma, are scheduled to host the Tennessee Titans next week.