Harvick took the lead on Lap 291 when Ryan Newman pitted, and he never relinquished it. Busch, who led a race-high 128 laps, was unable to track down the No. 4 car in the waning laps.
Here is a look at Sunday's top 10 finishers with full results available at NASCAR.com:
1. Kevin Harvick
2. Kyle Busch
3. Chase Elliott
4. Denny Hamlin
5. Martin Truex Jr.
6. Clint Bowyer
7. Aric Almirola
8. Daniel Suarez
9. Erik Jones
10. Kurt Busch
In addition to winning three straight races overall, Harvick has now won seven of the past 12 races at the former Phoenix International Raceway.
Harvick already topped the standings prior to Sunday's victory, and he extended his lead over Busch and Martin Truex Jr. with the win.
Here is a rundown of the current standings after Phoenix, per NASCAR.com:
1. Kevin Harvick: Leader (3 wins)
2. Kyle Busch: -12
3. Martin Truex Jr.: -12
4. Joey Logano: -16
5. Ryan Blaney: -16
6. Denny Hamlin: -31
7. Brad Keselowski: -34
8. Kyle Larson: -37
9. Clint Bowyer: -43
10. Aric Almirola: -45
11. Kurt Busch: -51
12. Austin Dillon: -54 (1 win)
13. Ryan Newman: -67
14. Paul Menard: -71
15. Erik Jones: -75
16. Chase Elliott: -77
By winning his third consecutive race, Harvick accomplished a feat that had not been done in NASCAR's Cup Series in three years, per Jeff Gluck of JeffGluck.com:
Although Harvick's place in The Chase became fairly secure when he won his first race of the season, Sunday's win was important based on what happened last week.
Harvick was docked playoff points after his win at Las Vegas when it was determined that his rear window did not meet NASCAR requirements.
As pointed out by Nick Bromberg of Yahoo Sports, Harvick alluded to the controversy during his celebration Sunday:
The first stage of Sunday's race saw Truex, Kyle Larson and Busch battling for the lead and the coveted playoff points that come along with a stage triumph.
Larson appeared ticketed for the stage win, but as seen in the following video courtesy of NASCAR's official Twitter account, Busch passed him late and came out on top in the opening stage:
All signs pointed toward Larson being a factor down the stretch, but he was knocked out of contention in the second stage.
Larson spun out, which resulted in him going down a lap and finishing 18th:
Kurt Busch took the second stage, which set up a third-stage showdown between several of the biggest names in the sport.
Hamlin, Kyle Busch, Keselowski and Newman all had stints in first place during the final 100 laps.
Newman attempted to play the odds by pitting out of turn, but when no caution flags came out, he was forced to pit under green on Lap 290:
That gave Harvick the lead, and he managed to stave off the rest of the field for the final 22 laps.
The fact that Harvick prevailed wasn't a big surprise considering Phoenix has long been his best track, but doing so in the face of adversity after last week's happenings was the most impressive aspect.
Harvick has now won 40 races in the NASCAR Cup Series, and he can afford to take chances for the remainder of the regular season.
Only an injury or a catastrophic run of bad luck could possibly keep Harvick out of the playoffs, and that gives him a huge advantage moving forward in terms of having the luxury to be aggressive in pursuing playoff points.