Coming off a disappointing finish at the Daytona 500, Harvick had the fastest car in practice and kept it rolling in the race, leading 224 of 312 laps on the odd-shaped mile oval.
Harvick won the fall race at PIR for Richard Childress Racing after Carl Edwards ran out of fuel at the white flag. Harvick needed no help Sunday, quickly moving to the front after starting 13th and pulling away on a series of late restarts to win in his second race with Stewart-Haas Racing. It was Harvick's fifth Sprint Cup win at PIR, most on the career list.
Daytona 500 winner Dale Earnhardt Jr. finished second, pole sitter Brad Keselowski was third and Penske Racing teammate Joey Logano fourth.
Jeff Gordon rounded out the top five on a warm and partly cloudy day after downpours wiped out the final 32 laps of Saturday's Nationwide race, won by Kyle Busch
Harvick won at Phoenix during the Chase for the Sprint Cup championship in the fall, giving him an outside shot at catching Jimmie Johnson for the series title in his final season with Richard Childress Racing. He came up short, but the victory and a third-place finish in the standings gave him a bit of momentum heading into for his first season with Stewart-Haas.
Harvick had a solid finish in his sights at Daytona last week before a last-lap crash dropped him to 13th.
At Phoenix, Harvick just missed the final stage of knockout qualifying, nipped by 0.001 seconds, but had the fastest car in Saturday morning's final practice session.
He started 13th and quickly moved his way through the field from the green flag, passing Keselowski on the apron, then Logano for the lead on lap 74. Harvick maintained the lead coming out of green-flag pit stops with just under 200 laps left and again with about 70 laps left.
A series of cautions came out late in the race and Harvick easily pulled away each time to earn a quick win with SHR on the same weekend he celebrated his 13th wedding anniversary with wife DeLana.
Earnhardt had a whirlwind week after winning his second Daytona 500, needing his girlfriend to get him extra clothes while he went on a media tour. He had a solid follow-up, putting the distractions aside to qualify fifth.
Earnhardt worked his way up in the opening third of the race, passing Logano and Keselowski to pull up behind Harvick. He dropped back a couple times and fought back to get Harvick within his sights again, but didn't have enough to track him down.
NASCAR's new knockout qualifying system made its Sprint Cup debut at Phoenix and Keselowski came out on top, edging Logano for his fourth career pole.
Not long after that, Keselowski found out he would be without his crew chief for the race; Paul Wolfe left the desert back to North Carolina for the birth of his first child.
With team engineer Brian Wilson and its Nationwide Series competition director Greg Erwin at the helm, Keselowski ran near the front all day, but, like everyone else, didn't have the speed to keep up with Harvick.
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