Arian Foster fumbled three plays later and the Jaguars recovered on the Houston 11. Jacksonville took advantage of the turnover when a wide-open Marcedes Lewis grabbed a 1-yard touchdown pass to push the lead to 27-17 later in the third.
Houston settled for a 27-yard field goal when the offense stalled inside the red zone to cut the lead to 27-20 near the end of the third quarter.
Houston took an early 7-0 lead when Schaub connected with rookie Martin on a 9-yard touchdown pass in the first quarter.
Gabbert was injured when he was hit by Danieal Manning and fumbled on Jacksonville's first drive.
Henne took over and the Jaguars evened it up when Lewis grabbed a 13-yard reception from him later in the first.
Cecil Shorts got in front of the defense on a 67-yard catch and run to give Jacksonville a 14-7 lead early in the second quarter.
The Texans answered with a 1-yard touchdown reception by tight end James Casey to tie it again.
The teams exchanged field goals late in the second quarter to leave tied at 17-all at halftime.
NOTES: Posluszny received four stitches on his forehead after being injured in overtime. ... RB Jalen Parmele had 80 yards rushing. .... Gabbert was 2 of 2 for 24 yards before leaving the game. ... Graham's two touchdowns were a career-high.