SPRINGFIELD, N.J. -- Jimmy Walker's day began at 7:40 a.m. ET and ended nearly 12 hours later with him lifting the Wanamaker Trophy on the 18th green as he won the 98th PGA Championship at Baltusrol Golf Club.

Thunderstorms on Saturday washed out the majority of the third round, so Walker and the rest of the final five pairings had to play 36 holes on Sunday to complete the championship. Because of the condensed schedule, which included starting the fourth round an hour after the final group teed off, players were not re-paired and the same duos went out on the course for Round 4.

For Walker, that meant playing both rounds with Robert Streb, who finished T7 at 8 under, and not Jason Day. Day was playing in the penultimate group with Emiliano Grillo, and the massive gallery usually reserved for the final pairing stuck with the defending champion rather than following the final pairing.

In a strange week at Baltusrol, it was fitting that the final round felt different. Walker, the 54-hole leader at a major championship, walked with a gallery that was a quarter the size of the one following Day for most of the afternoon.

The crowd at Baltusrol was waiting for the world's No. 1 player to rally up the leaderboard, but Day failed to give them the charge they craved. Day shot an even-par 34 on the front nine, and Walker never heard the roars that could have unnerved him early.

After two days of dreary, rainy conditions, the skies opened up briefly as the final groups made the turn, and a re-energized Day showed signs of life. He birdied the ninth to get back to even par and move one back of Walker. He birdied the 11th and murmurs began creeping up to Walker as he pushed into a tie at the top, but Walker was not fazed.

The eventual champion holed out a bunker shot for birdie on 10 to answer Day and stay one ahead. Then he doubled up on the birdie count on the 11th to pull two shots ahead, a gap Day could never close.

Walker came to the 15th hole and blocked his drive right and ended up under a tree. There was life for Day, who was two shots back with two par 5s yet to play. Day watched from the par-3 16th tee box as Walker hit his approach from under the tree, waiting, hoping for a little opening.

Walker knocked a wedge to 20 feet, leading to a two-putt par. At that point, it was clear that Walker wasn't going to simply fall back to Day and give him an opening, the world's No. 1 player would have to kick down the door.

Day parred the 16th and then grazed the lip on the 17th on a birdie putt, leaving him two shots back as he stepped to the 18th tee. The gallery was still with Day, even though the leader by two strokes was coming up the 17th fairway.

Day striped a 2-iron off the tee on 18. Walker cozied a layup just short of the bunkers on 17. With a left-front pin and bunkers lurking left, waiting for a mistake to short-side him, Walker took dead aim and zipped a wedge back to 8 feet.

Then the roar finally came. The roar that announced to Walker that there was work to do yet before he took home his first major.

Day stiffed a 2-iron on 18, leaving 10 feet for eagle. The crowd response rolled from the grandstands on 18 all the way back to the gallery that was left around the 17th green.

Walker knew what that roar meant; he was likely waiting for it to come all day. It alerted him that the defending champion was right at his side. The 37-year-old stepped up and poured in the putt, giving a knowing fist pump that one par on 18 would get it done.

"I heard Jason," Walker said. "I heard him hit the [2-iron] and I heard everybody was pumped, because he pumped one, I guess. And then I heard the second roar. So I knew I needed to make that putt, and I did."

The 18th hole was the easiest on the course all week, at least for the players without a major championship on the line that had made the 483 trips there before Walker.

The veteran hit iron off the tee -- like Day did in the group before him -- finding the fairway and taking the water out of play. Then, playing preferred lies as they had throughout the final round, he was able to place his ball exactly how he wanted it.

Day and Grillo were still on the green, so Walker stood there, watching and waiting. From 287 yards away, he saw Day pour in his eagle putt.

The grandstand shook behind the green. The roars cascaded down from the elevated green. Day was in the clubhouse at 13 under, one back.

Par was a must, and for the first time all day, Walker was facing the gallery you would expect to be following the leader of a major. He showed a little nerve, spraying a 3-wood right at the TV tower with his second shot, but he was near the green and remained confident.

"I said, 'Just send it up there as far as we can,' " Walker said. "I'm a great bunker player and a good pitcher of the ball. The ball just came out a little more right than I wanted to and made it a little more exciting."

Walker was left and short-sided with a bunker between him and the hole. He avoided the temptation for another hero shot and smartly flew it 34 feet behind the hole, needing two putts for his first major championship. He rolled the first putt 3 feet by the hole and then had to wait as Streb two-putted to clear the stage.

After collecting himself, Walker rolled it in to become the year's fourth first-time major winner, posting a bogey-free 67, his first bogey-free round in the 18 majors he has played.

"I said when I birdied 17, I figured that would probably end it. You think they are going to make three, and you're going to have to make a five. But you know, I'm standing out there and had a good front number and I'm like, 'Let's just send it up there,' " he said. "Nineteen out of 20 times, you're going to make a five going for this green in two. Made it a little more difficult than I would have liked, but awesome to make that last putt."

Walker didn't have to stare down Day and a massive gallery on Sunday, as one would normally have to do in the final pairing. That probably helped calm his nerves, but Walker still went out and won the damn thing.

He heard the cheers from Day's birdie on 11 and answered. He heard the first roar from Day's approach on 18 and answered. Then, knowing he needed a par on 18 after watching Day's eagle from afar, he was able to make the shots he absolutely had to.

Walker outlasted a stacked leaderboard, led by the world's No. 1 player, and never blinked. That's championship golf.