The rain-delayed Samsung Mobile 500 at Texas Motor Speedway left Hamlin singing "Monday, Monday, so good to me."
Still recovering from March 31 surgery to repair the ACL in his left knee, Hamlin took advantage of a wild late-race wreck that eliminated several of the fastest cars—including the dominant Chevrolet of Jeff Gordon—and held off fast-closing Jimmie Johnson to win his second race of the season and the 10th of his career.
Contrary to the sentiment of another popular song, rainy days and Mondays seem to buoy the spirits of Hamlin, who has won three of the past four NASCAR Sprint Cup races run on Monday.
Hamlin surged into the lead past Jeff Burton after a restart on Lap 323 of 334 at the 1.5-mile track. Johnson restarted fifth and dropped back in traffic before making a stirring charge in the final six laps.
With the surgery behind him, Hamlin vaulted from 18th to 11th in the Cup standings and reaffirmed his status as a contender for the series title.
"This is not the type of racetrack people characterize us being strong at," said Hamlin, who completed 376 laps at Phoenix last week 10 days after the ACL operation. "They always say we're a short-track team. When we won Homestead last year, it was a sign of things to come.
"I know we've got some good racecars in our stable. We're just going to keep getting better and keep working toward the Chase, and hopefully by the time we get there, we'll peak."
The victory was a bonus, considering that Hamlin opted to sacrifice his performance in the spring to get ready for the Chase for the NASCAR Sprint Cup, the 10-race playoff that starts in September at New Hampshire.
"I did it for the long run," Hamlin said of the surgery. "I did it for the Chase. I did it for the championship. … I'm still not 100 percent by any means. I feel like I'm 60 (percent) at best. We're still a month away from getting back where we were."
Kyle Busch, Hamlin's teammate at Joe Gibbs Racing, finished third, followed by Kurt Busch and Kasey Kahne, who announced on Wednesday he had signed long-term contract with Hendrick Motorsports and will leave Richard Petty Motorsports at the end of the season.
Mark Martin, Kevin Harvick, Dale Earnhardt Jr., Martin Truex Jr. and Greg Biffle completed the top 10.