Fitting, then, that in a week full of both, the sweetest surprise was waiting at the end, hidden behind sunglasses, but unmistakable in appearance and importance.

Amy Mickelson didn’t win her husband the 74th Masters. Guts and grit and skill — lots of that — went into the victory. But when Phil Mickelson arrived at the 18th green at Augusta National Golf Club yesterday in the shadow-filled glow of early evening, it was his wife he saw, and jubilation he felt. Winning does that. But sharing it with loved ones, especially in the midst of unforeseen personal hardship, does it one better.

So when Mickelson’s final birdie putt dropped, and a long, tight, tender hug finally was shared, a single tear rolled down his cheek. He won the golf tournament, and she’s winning a difficult fight against breast cancer. Two excellent reasons to become emotional.

“I don’t normally shed tears over wins, and when Amy and I hugged, that was a very emotional moment for us and something that I’ll look back on and just cherish,’’ Mickelson said. “I was just really glad she was there. I wasn’t sure if she was going to be there today.’’

For scorekeeping purposes, Mickelson was the only player in the final round not to make a bogey. Five birdies and 13 pars added up to a 5-under-par 67, a round good enough for a three-shot victory over Lee Westwood. It was Mickelson’s third Masters and fourth major championship, but the first time the 39-year-old lefthander from San Diego has won one of golf’s crown jewels since Amy’s diagnosis was announced last May.

With no guarantee that Mickelson would win — he began the day a shot behind Westwood — Amy stayed at the family’s rental house near the golf course, nervously following the action, unsure if she’d get the opportunity to make the short drive over, or if she’d even feel good enough to go. After seven straight pars were followed by a birdie on the eighth, and a bogey on the ninth by Westwood, Mickelson had the lead. When he birdied the 12th hole to break a tie with K.J. Choi, he had his wife’s full attention.

“I started crying at home on No. 12. That’s when I kind of saw him take control,’’ said Amy, who arrived in Augusta with the couple’s three children on Tuesday.

She was in the car and on her way to the course when her husband played the shot of the tournament. Faced with 207 yards for his second shot to the par-5 13th, Mickelson studied a small gap that two trees right in front of him were providing. A risky shot, but one he never hesitated committing to.

“I was going to have to go through that gap, if I laid up or went for the green,’’ Mickelson said. “The gap was . . . big enough for a ball to fit through. I just felt like at that time, I needed to trust my swing and hit a shot, and it came off perfect.’’

Mickelson’s 6-iron was true, finishing 4 feet away, and you’ll see the replay enough times that the fact he missed the short putt will probably be forgotten. This Masters had its signature moment, at least on the course.

The birdie doubled Mickelson’s lead to two over Westwood and a hard-charging Anthony Kim, who used a birdie-birdie-eagle-birdie stretch on Nos. 13-16 to get to 12 under.

On a day when everybody else gave shots back, Mickelson protected his lead with a vengeance. A two-putt birdie on the par-5 15th — Mickelson was 13 under on the par 5s for the week — gave him a three-shot lead, and when his tee shot avoided the pond on No. 16, victory seemed secure.

Westwood tried to make it interesting, making a birdie on the 17th to cut the lead to two. But Mickelson calmly dropped his 4-footer for par, taking a two-shot lead to the 18th tee and setting up his closing birdie.

“Phil shot 67, which generally wins major championships when people are [up] there going into the last round,’’ said Westwood, who now has a second and two thirds in his last three majors. “When you’ve come close, there’s a tinge of disappointment. But once that’s passed, I didn’t do too much wrong [yesterday]. I can walk away with a lot of positive thoughts and memories from this Masters.’’

Westwood isn’t the only one taking those with him. There were plenty of memories, starting with the ceremonial tee shots Thursday morning by Arnold Palmer and Jack Nicklaus, to the first-round 67 by 60-year-old Tom Watson, and the weeklong saga courtesy of Tiger Woods, who tied for fourth in his first tournament since November.

The lasting image, though, will be of a cute couple, dealing with disease, celebrating the good fortune that finally came their way.

“Not much was said,’’ Mickelson said, when asked what words were exchanged during the embrace.

Words weren’t necessary.