FOR YOU, DAD: Justin Rose points to the heavens on No. 18 to honor his father, Ken, who died of leukemia 11 years ago. Rose became the first Englishman since 1970 to win the U.S. Open (EPA)
ARDMORE, Pa. — One frenetic hour changed Justin Rose’s life forever yesterday and it left Phil Mickelson in a philosophical stupor.
Rose captured his first career major championship, winning the U.S. Open by surviving treacherous little Merion Golf Club, which many people thought would be vulnerable because of its length. He finished 1-over par for the championship after shooting a steely even-par 70 in the final round.
As for Mickelson, who finished in a tie for second with Jason Day at 3-over par, it was his record sixth runner-up finish in the U.S. Open, the tournament he covets most but cannot seem to cross the finish line first in.
“For me, it’s very heartbreaking,’’ Mickelson said. “I think this was my best chance — the way that I was playing heading in, the position I was in [entering yesterday with a one-shot lead] and the way I love the golf course.
“This one’s probably the toughest for me, because at 43 and coming so close five times, it would have changed the way I look at this tournament altogether and the way I would have looked at my record. Except I just keep feeling heartbreak.”
Mickelson wasted his early lead with double bogeys on Nos. 3 and 5, sandwiched around a birdie. He regained momentum — and the lead — when he holed a wedge from 75 yards for an eagle on No. 10. But he bogeyed three of his final six holes and the trophy slipped from his grasp.
“If I never get the Open,” Mickelson said, “then I look back and every time I think of the U.S. Open, I just think of heartbreak.’’
Rose will look back on this week as the greatest of his golfing life.
“It’s a moment where you can look back and think childhood dreams have come true,’’ said Rose, who missed the first 21 cuts of his professional career but persevered.
Rose made his home country proud, becoming the first Englishman to win a U.S. Open since Tony Jacklin in 1970.
Rose clinched his first career major by playing the 18th hole brilliantly considering its degree of difficulty and the pressure of the moment.
When he pumped his tee shot to the center of the fairway, the ball came to rest near the famous plaque for Ben Hogan’s iconic 1-iron 72nd-hole approach shot en route to a U.S. Open playoff win in 1950.
“I saw it and thought, ‘This is my moment,’ ’’ Rose said. “That image [of Hogan] is kind of hard to escape, that this was my turn to kind of have that iconic moment. I hit a good 4‑ iron and I felt I did it justice.’’
Rose’s approach shot rolled past the hole to the back fringe of the green. He bumped a fairway metal onto the green and nearly holed it for birdie and tapped in for par to finish at 1-over par — one shot clear of Mickelson, who was on the 17th hole.
When he was finished, Rose looked to the sky and pointed upward. Then, as he stood off the side of the 18th green digesting what just happened, Rose was visibly overcome with emotion, tears rolling down his cheeks.
“The look up to the heavens was absolutely for my dad,’’ Rose said of his father, Ken, who died of leukemia 11 years ago. “Father’s Day was not lost on me today. You don’t have opportunities to really dedicate a win to someone you love, and today was about him. My dad was the inspiration the whole day.
“I was trying to keep it together, obviously, because I didn’t want to be premature. Phil had two holes to play. But that was my time.’’
As Rose finished, Mickelson was down at the bottom of the quarry, staring at a 35-foot birdie putt, which he would miss. That left Mickelson needing birdie on the 18th, which had not yielded a birdie to a player all day.
Mickelson’s tee shot sprayed into the left rough, but the ball sat up, leaving him with a manageable lie. But he was 224 yards from the hole, needing to cut a shot right-to-left around the trees, and he came up about 30 yards short.
That left him with one pitch shot to force a playoff, and that slid past the hole to leave Rose as the champion. He two-putted for bogey, his third in his final six holes.
“I’ve been striving my whole life really to win a major championship,’’ Rose said. “I’ve holed a putt to win a major championship hundreds of thousands of times on the putting green at home. Preparing for this tournament, I dream about the moment of having a putt to win. I was pretty happy it was a 2-incher on the last.’’
mark.cannizzaro@nypost.com