LAS VEGAS — Brad Keselowski nailed the final restart and roared away from the field in the scorching Vegas heat. With another huge performance in his late-season surge, Keselowski finished up front again — and he’s got NASCAR’s “Big 3” looking over their shoulders. Keselowski raced to his third consecutive Monster Energy Cup Series victory Sunday, opening the playoffs by persevering through a wreck-filled afternoon and taking charge of overtime. He also secured team owner Roger Penske’s 500th victory across all competitions with his resourceful performance amid 99-degree conditions and constant stop-and-start late drama of a race featuring 12 cautions and several wrecks. “I didn’t think it was ever going to end,” Keselowski said after his 27th career victory and third in Las Vegas.