"It's just such a reliever for everyone on the team to get that win in early, and be able to enjoy the races and opportunities that we have instead of being stressed out about them," Keselowski said. "You know, I think if anything it actually lends itself to better racing."
Earnhardt also praised NASCAR's new Chase setup, which allowed him to take a fuel gamble in Vegas after winning already this season. Additional wins are worth bonus points in the Chase, while a second-place finish doesn't help his position much -- hence the motivation to go for broke on an empty tank.
"I think the new format is definitely is showing it has tons of positives," Earnhardt said. "It's better as far as entertainment for our sport. It gives us freedom, and it's nice to have that freedom to do the things that we did today, even though we knew our odds weren't good. We really shouldn't have made it, and we didn't, but we got to try because of the new system."
With his wife due to give birth at any minute, Paul Menard finished third in his Richard Childress Racing Chevy in front of Keselowski's teammate, pole-sitter Joey Logano. Edwards was fifth in a Roush Fenway Racing Ford, and Earnhardt teammate Johnson came in sixth.
The Las Vegas race is the first of 11 on 1.5-mile tracks, and NASCAR spent much of the offseason working on ways to improve the racing on these tracks with a new aerodynamics package and other improvements. The changes resulted in 23 drivers breaking the track speed record during qualifying, but the racing wasn't particularly thrilling until that final lap.
Keselowski and Earnhardt are the only two drivers to finish in the top five in each of the season's first three races, and they dueled down the stretch after Earnhardt passed him for the lead on a restart with 42 laps to go. Earnhardt had gone to the pits on the 211th lap and attempted to stick it out.
Keselowski was in fine form after his third-place finish in Phoenix last week without crew chief Paul Wolfe, who had returned home for his child's birth. Keselowski also finished third at Daytona.
Keselowski is the second driver to win both Vegas races in the same weekend, joining Jeff Burton in 2000.
Information from The Associated Press and ESPN Stats & Information was used in this report.