Texans 31, Chargers 28: Randy Bullock kicked a 41-yard field goal as time expired as Houston scored 24 unanswered points to stun host San Diego in Mike McCoy’s head-coaching debut.

The Texans trailed 28-7 before Matt Schaub threw two touchdown passes to get Houston within striking distance. Linebacker Brian Cushing then made a diving interception of a Philip Rivers pass and returned it 18 yards to tie the contest with 9:30 remaining.

Rivers passed for four touchdowns - two to Eddie Royal - for the fifth time in his career, but the Chargers (0-1) only produced 90 second-half yards while seeing their lead evaporate. Houston (1-0) began its winning drive with 3:53 to play and gained 38 yards to set up Bullock’s first career field goal.

Schaub passed for 346 yards and three touchdowns while Andre Johnson had 12 receptions for 146 yards, but the Texans got off to an inauspicious start. Schaub’s pass on the first offensive play was deflected by Jarret Johnson and intercepted by Cam Thomas at the Houston 14. Rivers followed by hitting Ryan Matthews for a 14-yard touchdown 15 seconds into the game, but the Texans tied it on Schaub’s 1-yard toss to Owen Daniels with 3:11 left in the quarter.

Rivers threw second-quarter touchdown passes of six yards to Royal and 10 yards to Vincent Brown for a 21-7 halftime advantage and added to the lead at the start of the third by hitting Royal for a 1-yard score. The Texans began their comeback on Schaub’s 7-yard pass to Garrett Graham and pulled within 28-21 when Daniels caught a 9-yard scoring toss 16 seconds into the final quarter.

GAME NOTEBOOK: Texans S Ed Reed (hip) didn’t suit up after offseason surgery. The former Baltimore Ravens star just recently began practicing. … Rivers threw three first-half touchdowns for the fourth time in his career. … Andre Johnson recorded his 45th career 100-yard receiving performance. … Chargers LB Manti Te’o, the team’s second-round pick, missed the game with a foot injury.