DARLINGTON, S.C. — Denny Hamlin has found the perfect way to rehab his surgically repaired knee — winning NASCAR races.

Hamlin became the first driver in 17 years to sweep the Sprint Cup and Nationwide events at Darlington Raceway, an achievement even more remarkable since he was on the operating table on March 31 to fix a painful ACL tear in his left knee.

Still, less than two weeks later, Hamlin was back in his No. 11 Toyota and barely missing a shift. Hamlin says the racing helps with the knee's recovery.

"It really is like a physical therapy session in there," Hamlin said of the driver's cockpit. "With the car, you have a little bit of vibration right there on the steering column. I kind of rest my leg against it."

Plus, at Darlington, Hamlin added a couple of therapeutic winner's burnouts.

Hamlin out-raced JGR teammate Kyle Busch to take the Royal Purple 200 on Friday night. At Saturday's Southern 500, Hamlin moved to the front late in the race and held on while prime contenders Jeff Gordon and Jeff Burton made pit errors to fall back.

It's been a quicker than expected recovery for an injury that may keep athletes in stick-and-ball sports off the field for months.

Hamlin injured his ligament playing basketball. After winning at Martinsville on March 29, Hamlin knew he couldn't drive without surgery. After the procedure, many at Joe Gibbs Racing held their breath about the season ahead — especially when Hamlin insisted jumping back in when the series went to Phoenix.

"We didn't know if he was going to make it the whole race, maybe half a race, what was he going to do," JGR team president J.D. Gibbs said. "I think he went up a few notches in my eyes (with) the mental toughness."

Hamlin's shown that the past month.

Hamlin followed a gritty, 30th-place finish in Arizona with a rousing win at Texas a week later.

Any lingering doubts about his condition were put to rest at Darlington.

He led 111 of 147 laps in the Nationwide event, roaring ahead of Busch over the final five laps to capture his second series win this year. Hamlin said after the victory that he took steps to conserve his energy with a grueling, 500-miler ahead.

Hamlin again led the most laps in the Southern 500 — 104 out of 367 laps — and was again up front when it mattered most.

He outpaced pole-sitter Jamie McMurray in second, Kurt Busch in third and Jeff Gordon in fourth.

Series points leader Kevin Harvick extended his margin with a sixth-place finish, while Jimmie Johnson got caught up in two wrecks and didn't finish.

Hamlin's gumption wasn't a revelation to JGR, even if his three victories the past six races are.

"I'm personally surprised that we're running as strong as we are," Hamlin's crew chief, Mike Ford, said.

Hamlin was asked what his ironman effort at Phoenix showed about himself and, at first begged off an answer. When pressed, Hamlin said it showed his character and desire to work with his team.

"The easy way would have been to get out of the car, sit there, watch someone else go through hell the rest of the race with a car that was dinged up," Hamlin said.

"There's been many times my guys have gone over and beyond for me in certain situations and stuck up for me," Hamlin continued. "I felt like it was important for me to step up and do the same for them."

While Ford appreciates the sentiment, he understands there's more at work with a competitor like Hamlin.

"Heck, knowing Denny, I knew he would never even think about getting out of the car," Ford said. "We just kind of rolled with it."

Now, Hamlin may be headed to the biggest roll of his life.

Hamlin entered the season a trendy pick to unseat four-time NASCAR champion Johnson. However, the injury and a slow start seemed to send those hopes into the wall.

Hamlin, though, says everything's improving — his knee, his team and his drive for NASCAR success.

There may be a downside for Hamlin, though.

"For the record," J.D. Gibbs told his driver, "'If you ever break your ankle, wrist, I don't want to hear it. You're driving the car.' So we got that settled."