OAKLAND, Calif. -- The all-important third preseason game for Matthew Stafford and the Detroit Lions turned out to be a real Bay Area bruiser.

At least for a moment, the season almost appeared broken.

Stafford threw for 68 yards until leaving with an injury to his non-throwing hand in Detroit's 31-20 loss to the Oakland Raiders on Saturday. The 2009 No. 1 overall pick sat on the sideline and watched in horror following the helmet-to-hand hit in the second quarter.

"It was just scary to look down and see your hand swelling up by the second," Stafford said. "That kind of freaked me out. The skin kind of just grew by the second. I didn't know what was going on."

Defensive end Dave Tollefson drove Stafford to the ground after an incomplete pass and his helmet collided with Stafford's left hand. Team trainers wrapped Stafford's hand in heavy bandages and a brace on the sideline. X-rays were negative, and Shaun Hill took over on Detroit's next possession.

Oakland sidelined several more Detroit players.

Cornerbacks Bill Bentley departed with a shoulder injury and Chris Houston with a left ankle injury in the first half for the Lions. Running back Kevin Smith also left with what appeared to be a more serious right ankle injury. X-rays on his ankle were negative.

All are expected back by the regular-season opener against St. Louis on Sept. 9. However, all -- including Stafford -- were uncertain if they'd play in the preseason finale Thursday at home against Buffalo.

"More than anything, I was just really scared," Smith said. "I've had a high-ankle sprain before and know how long it took to get back healthy. But it's not a high-ankle sprain, so that's positive."

The Raiders remained mostly injury free -- one of the bright spots from the starting unit -- and relied on backup Terrelle Pryor to provide the spark.

Carson Palmer again lacked the poise and polish of a seasoned veteran, dazzling at times with crisp passes, but also throwing two interceptions in another on-again, off-again performance. The second interception, however, was bobbled by Eddie McGee and into the hands of linebacker Stephen Tulloch.

Palmer completed 17 of 26 passes for 181 yards until he was replaced by Pryor in the third quarter.

Pryor scrambled for 59 yards and later shook off a sack for a 17-yard touchdown run. The former Ohio State standout also threw a 39-yard TD to Juron Criner, who twisted back to haul in the underthrown ball over a defender, and a 76-yard pass across his body to Criner running a post pattern across the middle for another score.

Pryor's final line: 3 of 5 for 137 yards and two touchdowns. He also ran for 90 yards and a score on five carries. He dedicated the victory to his father Craig and mentor Theodore Sarniak III. Both died in the span of a week in July.

"I love this feeling," said Pryor, taken in the third round of the supplemental draft last year. "And I want more of it."

The highlights for Oakland's first-team offense were limited.

Darrius Heyward-Bey caught a 41-yard pass between the hands of Justin Miller in the second quarter for the longest completion by Palmer of the preseason. Darren McFadden fumbled on Oakland's fifth play inside the 1-yard line, rookie coach Dennis Allen challenged the call and officials ruled the running back crossed the goal line before losing the ball to put Oakland ahead 7-3 lead.

Willie Young intercepted Palmer's pass at Oakland's 7-yard line but Hill threw incomplete to Calvin Johnson on fourth-and-1 as Detroit's offense stalled again.

"We definitely made some progress but we need to clean some things up once we get down there in the goal line and get in earlier than we did," Palmer said.