As we celebrate the 50th anniversary of the US Open, we look back at the 50 champions who have left an indelible mark on this inimitable event.

At his dogged best, Rafael Nadal is perhaps the most physically-intense competitor ever to play the game. Defeating an in-form Nadal in a best-of-five US Open match is akin to running the New York marathon – while sprinting through the entire city course.

In 2010, the Spaniard cracked the code for what was the final leg of his career Grand Slam, adapting his game to find success on the hard courts of the US Open after seven barren years. Now, having competed in 13 US Opens to date, Nadal’s 84 percent winning percentage at the tournament is second only to his near-perfect 98 percent mark at the French Open.

The King of Clay has reigned over the hard courts of New York three times in his career, winning the US Open crown in 2010, 2013 and 2017. He is one of just six men in the Open era to win three US Open singles titles, a feat made even more impressive by his early-career struggles at the event.

Nadal’s success is fueled by his ability to defend and attack with equal ferocity. It has always been a lethal combination on the slower clay courts, but on faster surfaces, the onus is on the latter skillset – the ability to strike first and dictate points.

The 32-year-old’s improvement in that area and his ultimate success in New York are testaments to the relentless work ethic that has defined both his game and his career.

Throughout the 2010 tournament, much attention was paid to Nadal’s newly-bolstered serve. He added 10-12 mph to his first and second serve average speed from 2009, according to a 2013 USA Today article, and routinely clocked 135 mph on the radar gun. It was a big change from his previous delivery which relied more on spin than speed, and it immediately reaped rewards.

Nadal won 95 percent of his service games in the 2010 tournament, dropping serve just twice on his way to the final.

In the press, Nadal attributed some of the improvement to a minor grip change, but was quick to downplay the significance of the adjustment.

To him, it was just another small improvement, one of many he had made to his game throughout years of dedication to the sport.

“All my life I’ve worked on my serve,” Nadal said at a 2010 US Open press conference. “Not this summer, no. All my life.”

play video 50 for 50: Three-time men's champion Rafael Nadal

Nadal entered the 2010 tournament as the world No. 1 on the heels of French Open and Wimbledon victories. But in consecutive US Open semifinal appearances in 2008 and 2009, he won just one set in two matches as he bowed out to Andy Murray and Juan Martin del Potro.

He was improving on the hard courts, but far from satisfied. Already a legend with eight career Grand Slam titles, Nadal still had a point to prove.

Armed with that extra pop on his serve, the then 24-year-old stormed into the final without dropping a set before defeating longtime rival Novak Djokovic in four sets for the title.

After seven fruitless attempts, Nadal could finally take his trademark bite into the Big Apple trophy. The victory made him the youngest man to win the career Grand Slam in the Open era and the first to win a major on clay, grass and hard courts in the same calendar year.

After reaching the final again in 2011 and missing the 2012 event with a knee injury, Nadal reclaimed the title in 2013 with another four-set victory over Djokovic, avenging his 2011 final loss to the Serb. He followed that up with a French Open title in 2014, his ninth in Paris and 14th overall.

In 2015, Nadal dropped out of the Top 5 for the first time since 2005. It seemed years of unremitting physical play had taken a toll as he battled numerous injuries and got no further than the quarterfinals at any major after his 2014 French Open run.

Until 2017, that is.

When the No. 9-seeded Nadal and No. 17 Roger Federer conjured up a pair of magical runs to the 2017 Australian Open final, the tennis world savored the renaissance while wondering how long the 30-plus-year-old legends could keep it up.

That spring, Nadal reclaimed ownership of the clay-court season with a trio of trophies in Monte Carlo, Barcelona and Madrid, with the latter being his 30th career Masters trophy (he now has a record 32).

His dominance continued with a 10th French Open title, and he returned to New York as the world No. 1.

His third US Open title all but clinched the year-end No. 1 ranking, and the only thing that was missing was a long overdue battle with Roger Federer. Despite meeting 38 times in their careers, and 12 times in Grand Slams, the pair have never squared off in New York.

Nadal’s 17 Grand Slam titles make him second all-time, behind his longtime Swiss rival, on the list of men’s major winners. But the Spaniard holds a decided edge in the head-to-head battle, with a 23-15 overall advantage and a 9-3 mark in the majors.

The pair will forever be linked, having dominated the game for so long, and being four years younger, Nadal may yet catch his friend in the Grand Slam count. But, as he said after winning his record 11th French Open title in June, he is not “crazy” about the chase.

His motivation remains intrinsic; he simply wants to keep fighting and keep improving, just as he has done his entire career.

Like with his serve in 2010, and as he simply put it in 2015, undeterred after a third-round US Open loss:

“Just improve the small things that make a big difference.”

50 Fact: Nadal holds the record for consecutive years with at least one Grand Slam trophy, as he won at least one major title each year from 2005-2014.