DETROIT – Jim Schwartz threw a challenge flag when he didn’t need to and the Houston Texans made him regret it.

Shayne Graham’s 32-yard field goal with 2:21 left in overtime Thursday lifted Houston to a 34-31 victory against the Detroit Lions after their coach broke an NFL rule by attempting to challenge a scoring play.

“Obviously that’s a big break in the game for us,” Houston Coach Gary Kubiak said. “But I think you make your breaks when you work your tail off.”

Detroit kicker Jason Hanson had a chance to get Schwartz off the hook, but his 47-yard field-goal attempt on the fifth possession of overtime hit the right upright.

Also, Lions defensive end Kyle Vanden Bosch on the previous possession couldn’t intercept a pass Matt Schaub threw directly at him deep in Houston territory.

Detroit might have won in regulation if its coach didn’t make a costly mistake.

Schwartz threw a challenge flag when Justin Forsett of Houston scored on an 81-yard touchdown run in the third quarter after two Lions tackled him.

“Give him credit for continuing to play football,” Kubiak said. “We talk about that all the time. You don’t stop, you play.”

Replays showed Forsett’s left knee and elbow hit the turf near midfield, and the automatic review that accompanies all scoring plays probably would have taken the TD off the board. But NFL rules say throwing the challenge flag on a scoring play negates the review — and is an unsportsmanlike conduct penalty to boot.

“It’s on me,” Schwartz could be seen saying to assistants and players on the sideline as he tapped his chest. “It’s on me.”

Forsett even acknowledged he shouldn’t have been allowed to score.

“I know now that I was down but I didn’t think I was during the play,” he said. “I didn’t think my knee hit and there was no whistle, so I kept going. I wasn’t giving the touchdown back.”

That score pulled Houston within three points.

“I knew the rule — you can’t challenge on a turnover or a scoring play — but I was so mad that I overreacted,” said Schwartz, whose temper got the best of him during a postgame handshake last year with San Francisco Coach Jim Harbaugh. “I had the flag in my hand before he even scored because he was obviously down.”

Kubiak had no sympathy.

“A rule’s a rule,” Kubiak said. “I know one thing: You’ve got to keep your flag tucked in your pocket.”

Arian Foster ran for 102 yards and two scores, including a 1-yard run with 1:55 left in the fourth quarter to cap a 15-play, 97-yard drive that made it 31-31.

Houston (10-1) took its first lead when Graham made up for missing a field goal earlier in overtime after teammate Danieal Manning ripped the football from Lions tight end Brandon Pettigrew at its own 32 on the first drive of overtime.

The Texans have won five straight — two in a row in overtime — and if a handful of teams lose they could be in the playoffs by the time they get on the practice field after a long weekend.

“Ten quarters in five days, it’s draining physically and mentally,” Texans defensive end J.J. Watt said. “But our team persevered.”

And the Lions (4-7) wilted and blew a fourth-quarter lead during a second straight setback.

REDSKINS 38, COWBOYS 31: Robert Griffin III threw for 311 yards and four touchdowns, helping Washington win at Arlington, Texas.

The Heisman Trophy winner from Baylor made the Cowboys (5-6) look like an overmatched college team during the decisive second quarter in his first trip to Texas as a pro.

Griffin was 8 of 8 for 178 yards with three touchdowns to key the first 28-point quarter in 13 years for the Redskins (5-6). The rookie became the first Washington quarterback to throw four touchdown passes in consecutive games.

Dallas quarterback Tony Romo lost for the first time in six starts on Thanksgiving, despite a career-high 441 yards and three second-half touchdowns, including a career-long 85-yarder to Dez Bryant.

NOTES

COWBOYS: Receiver Miles Austin, cornerback Orlando Scandrick and linebacker Bruce Carter left the game against Washington due to injuries.

BRONCOS: Cornerback Tracy Porter practiced fully and will travel to Kansas City with the team for Sunday’s game.

FALCONS: Receiver Julio Jones, who has a sore right ankle, was limited in his return to practice.

TEXANS: Linebacker Brooks Reed left the game against Detroit with a groin injury and didn’t return.

BILLS: Cornerback Leodis McKelvin acknowledged he was wrong and won’t dispute a $75 fine for failing to follow a crew member’s orders during a flight from New York to Buffalo. McKelvin was ticketed for refusing to turn off his cellphone and failing to buckle his seatbelt.