When Rory McIlroy sauntered down the 18th fairway Sunday evening – cap already doffed, smile already wide -- he could have dropped shots from his pockets with each stride and still won the U.S. Open comfortably. He had some time, then, to look into the crowds at Congressional Country Club – galleries that plugged the massive grandstands, that lined the banks of the adjacent pond, that filled the roof of the clubhouse. He needed to spot one green shirt, his father Gerry, on Father’s Day.

“I was looking for him,” McIlroy said.

There was the enormity of what was happening, and what was being said, around him. McIlroy won the U.S. Open title – a victory he kept referring to as his “first major championship,” as if more are in the offing – in a style that fell completely in line with his potential and promise, and felt very much like history.

He set an Open record at 16 under par. He set an Open record with his 72-hole total of 268. At 22, he became the youngest major champion since Tiger Woods. Two months after downright blowing the Masters, he completely owned the next major to be played, leading by three after one round, six after two, eight after three and eight to win.

So it seemed, immediately, the question became: What next? For that, go to the man who knows him better than any other.

“After the Masters, after winning this, I think he’ll just go on,” Gerry McIlroy said. “He’ll go on leaps and bounds. He should do well. And he’s keen to do well. He’ll keep working, if I know Rory.”

There are numbers that must be dealt with, and they are worth stating. But given the reaction – from the galleries, from his peers, from his predecessors – this was more significant than sheer mathematics. What McIlroy accomplished here may not have the social overtones of Woods’s command performance at the 1997 Masters, nor the degree of dominance of Woods’s win in the 2000 U.S. Open, when he beat the field by 15 strokes – a mark McIlroy couldn’t match Sunday.

Consider, though, the figure McIlroy is now cast against – none other than Woods, this Open’s most notable absentee – and it is solid evidence that what he pulled off could portend a change for his sport. For 15 years, Woods’s presence and performance has determined whether golf is up or down, in or out.

“He’s the best player I’ve ever seen,” said Graeme McDowell, McIlroy’s countryman and the 2010 U.S. Open champ. “He’s a breath of fresh air for the game, and perhaps we’re ready for golf’s next superstar. Maybe Rory is it.”

To be sure, McIlroy slayed a rain-softened Congressional course that laid along River Road without so much as a jackknife to defend itself. Still, he not only became the first player to ever reach 13 under at any point in a U.S. Open, but he became the first to 14, 15, 16 and 17 under as well. His four-round total blew away the previous record of 272, accomplished four times, most recently by Jim Furyk in 2003.

He made four scores of bogey or worse all week. With his 2-under 69 Sunday, he became the third player – joining Lee Trevino in 1968 at Oak Hill and Lee Janzen in 1993 at Baltusrol – to post four rounds in the 60s. On and on.

Poor Jason Day, the runner-up. He was eight strokes back. Poor Y.E. Yang, his playing partner the final two days. He shot 70-71 on the weekend at a U.S. Open – and lost ground.

“I think he’s still growing,” Yang said through an interpreter, “and it’s just scary to think about it.”

That is the consensus in golf, and nearly everyone – near and far – was asked his opinion. Woods, owner of 14 major championships, said, “What a performance,” in a remark forwarded from his agent. Jack Nicklaus, with 18 majors, spoke about McIlroy during NBC’s broadcast of the final round, then later in an interview released through his publicist.

“To win the U.S. Open, and have that happen to him at this age,” Nicklaus said, “it takes a lot of pressure off him, but also puts a lot of pressure on him.”

He may, now, be equipped to deal with it. Twenty minutes after that wretched round at the Masters – an 80, in which a four-shot lead disappeared -- he called his father. Gerry McIlroy’s first words: “Rory, are you okay, son?”

“You always feel for your kids,” Gerry said.

Rory’s response came quickly.

“He said, ‘Dad, I have no problem with it at all,’ ” Gerry said. “‘I hit a few bad shots.’ And if you play golf, you understand that. And that was it.”

He came to Congressional a week early and twice played practice rounds. “It’s fantastic,” he said when he was done. The vibe was good.

“He told me, ‘I think I can shoot a score around here,’” said his caddie, J.P. Fitzgerald.

He did better than that. When he came to the 10th tee Sunday, he led Yang by nine, with a 214-yard shot at the par 3 over water ahead. Yang stuck his ball to six feet. But here was McIlroy’s week: He pulled a 6-iron, made what Fitzgerald called “a tremendous strike,” poured the ball perhaps eight feet back of the pin, and watched it trickle to maybe four inches, a near ace.

“I thought that was probably the biggest point in the round,” McIlroy said.

As golf shots go, sure. But at 18, he had only a foot left for his closing par when he looked across the green. There, he caught his dad’s eye, smiled wide and gave a small fist pump. They had shared their first golf lessons 20 years ago. They had shared breakfasts all week. They had one more moment to share, and after he putted out, Rory embraced his father greenside, each slapping the other’s back.

“I feel like, with my dad, I can share things with him that maybe I couldn’t do with a friend of something like that,” McIlroy said.

Before he returned to the 18th green for the post-tournament ceremony, McIlroy had some menial tasks to tend to – signing his scorecard, fishing his two iPhones from his golf bag – in a small trailer behind the grandstands. After he hugged his father again, a security guard came forth.

“Are you ready, guys?” he said.

“Yeah, yeah,” McIlroy responded, instantly and confidently.

“Okay, let’s go,” the guard said, and Rory McIlroy went. He walked back to the 18th green to receive the trophy for his first major championship. How many more times he will make that walk, how many more majors he will win, can’t be known, but the whole scene felt comfortable, repeatable, familial.

“I really can’t put it into words,” Gerry McIlroy said. “What he’s done has been fantastic.”