DETROIT (AP) -- Steve Mariucci struggled to get too excited about a preseason victory because a handful of Detroit Lions went down with injuries.

On the opening drive, the Buffalo Bills got exactly what they wanted, while the Lions couldn't avoid their worst fear in the final exhibition for both teams.

Drew Bledsoe led Buffalo's first-string offense to its only touchdown of the preseason, three Detroit defensive backs were hurt and the Lions went on to beat the Bills 20-17 Thursday night.

"It's nice to get out with a win -- I suppose," said Mariucci, in his second season with the Lions. "But that first series was crazy. I didn't know what to do."

Lions safety Brock Marion (bruised right knee), cornerback Fernando Bryant (neck stinger) and cornerback Rod Babers (shoulder) all left the game with injuries.

Bryant was hurt on the second play from scrimmage, Marion went down three plays later and Babers was also hurt during the first possession.

"I said, 'You've got to be kidding me," Lions president and general manager Matt Millen said.

Marion was later carted away from the sideline with an ice pack strapped to his knee, but X-rays were negative. He was to have a follow-up MRI exam.

Bryant is a starter, and Babers is competing for a roster spot.

"I didn't know what was happening at first, because my arm went completely numb," Bryant said. "But after a minute, I knew it was just a stinger. I've had stingers before. It's nothing. It's part of football."

Starting linebacker Donte Curry (left thigh) also left the game in the first quarter, but said the injury wasn't serious.

Last year, Detroit lost James Stewart for the season with a shoulder injury in the first quarter of the final preseason game against Buffalo.

The Lions (2-2) went ahead for good late in the third quarter when Rick Mirer lobbed a 26-yard TD to David Kircus, giving them a 20-17 lead.

Bledsoe was 4-of-6 for 62 yards on his only possession, a 16-play, 90-yard drive. He threw a perfect 21-yard deep out to Eric Moulds against Dre' Bly to set up a TD.

"I think we finally finished (a drive)," Bledsoe said. "Prior to that drive, we'd done some good things and moved the ball a little bit. But we always had that one thing that stopped us."

Willis McGahee, still looking tentative coming off his knee injury, gained just 24 yards on 11 carries, but put Buffalo ahead 7-0 with a 2-yard run. Travis Henry missed the game with bruised ribs, but is expected to start the opener against Jacksonville.

Most importantly, the Bills (1-3) got out of the game healthy after losing two backup quarterbacks to injury last week.

"You want to come out of this thing for the real deal," Bills coach Mike Mularkey said. "To me, it seemed like a long game. The third quarter was an hour, it felt like."

Shane Matthews, signed Monday, relieved Bledsoe and was 7-of-10 for 104 yards.

"He was pretty impressive," Mularkey said.

The Lions started backup quarterback Mike McMahon to prevent Joey Harrington from getting hurt. McMahon was 8-of-16 for 84 yards and a TD.

On McMahon's TD pass, he rolled right and threaded a throw between two Bills and into Tai Streets' hands in the back of the end zone. He led two drives to field goals, including Jason Hanson's 33-yard kick just before halftime to put the Lions ahead 13-10.

"The more you play, the better you'll be because you can only get so much better in practice," McMahon said.

Shaud Williams' 4-yard run, capping a 93-yard, Matthews-led drive, gave the Bills a 17-13 edge midway through the third quarter.

Game notes
The Lions will look to snap their NFL-record streak of 24 straight losses in their opener at Chicago. ... Williams ran for 78 yards on 18 carries. ... Running back Shawn Bryson led the Lions with two catches for 28 yards. ... Buffalo receiver Drew Haddad caught three passes for 61 yards.