TAMPA, Fla. -- Bobby Rainey's never lacked confidence in himself. All he wants is an opportunity to show he can play in the NFL.

"That's my motivation, when people tell me what I can and cannot do," the diminutive running back said Sunday after rushing for 163 yards and scoring three touchdowns to help the Tampa Bay Buccaneers dominate the Atlanta Falcons 41-28.

Picked up on the waiver wire last month, Rainey is playing for his third team in less than two seasons. This performance came six days after he carried the ball for the first time with Bucs and played a key role in helping them get their first win.

"To come back and do it again today was huge," Rainey said.

The 5-foot-8, 212-pounder whose lack of size hurt his chances of being drafted is making his mark while filling in for the injured Doug Martin and Mike James.

Rainey scored on first-half runs of 43 and 3 yards, then caught a 4-yard TD pass from Mike Glennon in the third quarter to help the Bucs (2-8) win for the second straight time following an 0-8 start.

The previous week, he rushed for 45 yards and scored the go-ahead touchdown in a 22-19 victory over Miami. He began the season as a kick returner and backup running back with the Cleveland Browns.

"He's stepped up. We put a lot on his plate, but he's handled it well," receiver Vincent Jackson said.

"He's being very coachable. He's taking in everything that's being asked of him, doing a great job in the passing game as well, picking up blocks," he said. "I see the kid being successful the rest of this year. We put guys in position to be successful. Hats off to our coaches for working with him, putting the time in so he can go out there and compete."

Matt Ryan threw an 80-yard TD pass to Harry Douglas, extending his streak of consecutive games with at least one touchdown to 16 games. He threw a 6-yarder to Roddy White in the fourth quarter, but also was sacked three times by Tampa Bay's Gerald McCoy and had one of two interceptions returned 37 yards for a TD by linebacker Mason Foster.

The Falcons (2-8), who went a NFC-best 13-3 and finished one victory shy of the Super Bowl last season, have lost four straight by a combined score of 135-61.

"It's embarrassing, the way we came out and performed as a team. I mean all of us," Atlanta tight end Tony Gonzalez said. "It's all of us. (I'm) getting tired of it. It's all of us. That's the thing about it. It's going to take all of us to get out of it."