Hauschka's boot with 3:19 left in the extra frame came after Richard Sherman picked off Matt Schaub and ran 58 yards for the tying score with 2:40 left in regulation.
Shortly before that, Russell Wilson had led the Seahawks on a 14-play, 98-yard drive, capped by a Marshawn Lynch 3-yard TD run that cut the deficit to seven points.
Wilson went 12-of-23 through the air for 123 yards with an interception while adding 77 rushing yards on 10 carries for the Seahawks (4-0), who remained unbeaten after four games for first time in franchise history.
Lynch ran for 98 yards on 17 attempts in the victory.
Matt Schaub made good on 31-of-49 passes for 355 yards with two TDs for the Texans (2-2).
Arian Foster led Houston's ground game with 102 yards on 27 carries.