TAMPA, Fla. -- - Ty Simpson helped No. 10 Alabama shrug off a slow start and beat South Florida. What wasn't certain Saturday was whether the third-stringer played well enough to become the Crimson Tide's starting quarterback.

Simpson came off the bench and led two long touchdown drives, while Roydell Williams paced a productive rushing attack with 129 yards and a TD.

As a result, the Crimson Tide (2-1) rebounded from a 10-point loss to Texas and improved to 14-1 in games following a regular-season loss since 2008.

To do it, though, Alabama had to overcome inconsistent quarterback play and several costly mistakes that kept USF (1-2) in the game. The Bulls led 3-0 when lightning delayed play for 55 minutes in the second quarter, and it was 3-3 at halftime.

"I know you're going to ask about the quarterbacks, but we're going to evaluate (them) on how they played today and evaluate Jalen Milroe on how he played (in two starts)," Crimson Tide coach Nick Saban said. "We'll decide this week who gives us the best opportunity to be successful as an offensive team, and that's the way we'll go."

Notre Dame transfer Tyler Buchner started at quarterback for Alabama in place of Milroe, a duel-threat redshirt sophomore who lost his grip on the No. 1 job after the offense sputtered in the previous week's 34-24 loss.

Buchner wasn't any more effective, completing just five of 14 passes for 34 yards before Saban turned to Simpson when linebacker Dallas Turner forced a USF fumble to set up Alabama at the Bulls 25 after the weather delay.

Simpson turned the turnover into Will Reichard's 30-yard field goal that made it 3-3. He finally got the Crimson Tide in the end zone, using a 45-yard completion to C.J. Dippre to fuel a six-play, 84-yard drive that Roydell Williams finished with a 1-yard TD run for a 10-3 lead with 4:35 remaining in the third quarter.

"I know we struggled a little bit on offense," Saban said. "We ran the ball fairly well, better in the second half than we did in the first. I'm really proud of our players for the way they competed. I need to do a better job of getting them ready to play in games like this. We were a little flat in the beginning, but after the rain delay I thought we competed better."

Alabama hurt itself early, with Kool-Aid McKinstry's losing a fumble on a first-quarter punt return to set up John Cannon's 44-yard field goal for USF and Jeremiah Alexander's holding penalty that wiped out what would have been Terrion Arnold's 100-yard return for a TD on the ensuing kickoff.

Simpson finished 5 of 9 passing for 73 yards without an interception. He capped the victory by ending an an 11-play, 80-yard drive in the closing minutes with a 1-yard TD run. Alabama amassed 203 yards on the ground, with Jase McClellan gaining 70 of his 74 yards in the first half.

"I know we've got the SEC (conference play) coming up next week and obviously we've got a lot of things to fix and we'll work on it," Saban said. "We've had four touchdowns this season negated by penalties. A kickoff return today, a touchdown run today and two last week. We need to fix all those things."

Byrum Brown completed 14 of 28 passes for 87 yards and one interception for USF. He also ran for a team-leading 97 yards on 23 attempts as the Bulls gained 177 on the ground.

USF's lone scoring drive covered four yards.

"There are no moral victories. Valiant efforts are for losers. Moral victories are for losers," USF coach Alex Golesh said.

"That's what losers say: `Winners win,'" Golesh added. "So, there are no moral victories, there are no valiant efforts, there are no anything, We played winning football on defense, we played well enough (defensively) to win that football game."

THE TAKEAWAY

It wasn't pretty, but Alabama accomplished the expected in extending its impressive streak of not losing consecutive regular season games since 2008. The only back-to-back defeats over that stretch came when the Crimson Tide lost to Auburn in the 2013 regular-season finale and then fell to Oklahoma in the 2014 Sugar Bowl.

USF, rebuilding under first-year coach Alex Golesh after going 1-11 last season, has lost 15 in a row to ranked opponents.

POLL IMPLICATIONS

Alabama dropped seven spots in the Top 25 after losing at home to Texas. Struggling on the road against a team that had dropped 11 in a row before beating FCS foe Florida A&M the previous week likely won't help the Crimson Tide much in the next poll.

UP NEXT

Alabama returns home for its Southeastern Conference opener against No. 17 Ole Miss.

USF hosts Rice in its American Athletic Conference opener.