Yet, one by one the big names dropped in Flushing Meadows. First Andy Roddick went out on the first Saturday and then Andy Murray lost in straight sets, 7-5, 6-2, 6-2, to Marin Cilic, a few days later.
 
In the Semifinal rounds, Novak Djokovic was taken out by Roger Federer, while Del Potro beat up Rafael Nadal in straight sets, 6-2, 6-2, 6-2. But Nadal, who was nursing an abdominal strain and forced to play on back to back days, if healthy, it was thought the No. 3 seed would have taken care of the 20 year-old from Argentina.
 
No one was giving Del Potro much of a chance in the Finals when he had to face Federer. The Maestro was gunning for his sixth consecutive Open title, and although he had a scare or two along the way, the world's best player seemed poised to raise the silver trophy again. Federer won two Grand Slams so far this year and he lost in Australia in five sets to a healthy Nadal.
 
Del Potro, it was thought, was just a step below the elite.
 
But this is why they play the match.
 
A five-set classic in Flushing Meadows – the first championship that went five in 10 years – saw the young Argentinian break down Federer's game, with a series of laser-like forehands and an on the mark serve, to take the Open, 3-6, 7-6 (5), 4-6, 7-6 (4), 6-2.
 
“I thought it was a tough match from the start,” Federer said. “I think even the first set was, you know, pretty close. I think both getting used to the conditions. It was kind of tough starting around the 4:00 time because the shadows moving in and stuff.”
 
“I got off to a pretty good start, and had things under control as well in the second set. I think that one cost me the match eventually. But I had many chances before that to make the difference. So it was tough luck today, but I thought Juan Martin played great. I thought he hung in there and gave himself chances, and in the end was the better man.”
 
Del Potro was understandably nervous as the first set started. Although Federer said it was tough, it looked very easy for the Maestro. In total control, Federer cruised to a 6-3 win and then was up a break in the second, until Del Potro was able to compose himself.
 
“Yes, the beginning of the match I was so nervous, I didn't sleep last night,” Del Potro said. “I didn't have breakfast today. That's part of the final, you know. But Roger started very good. I start little down. I was bad with my serve, and that's an important weapon of my game. When I broke his serve for the first time, I started to believe in my game. To change.”
 
Del Potro broke Federer back and forced a tie break in second. He was able to break Federer in the fifth serve to eventually tie up the match.
 
“I thought I had him under control for the first two sets,” Federer said. “I should never have lost so many chances. It was just a pity. I think if I win the second set, I'm in a great position to come through. Unfortunately, I didn't win that and that was it.”
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In the fourth, though, things started to unravel for Federer as Del Potro's 62 percent first serve came out. He was on the mark more and was able to return with a forehand that was clocked at over 110 m.p.h. Ultimately, it was in the fourth where Federer lost the match as he was two points away from the championship and couldn't close.
 
Del Potro took control in the fifth set, where he broke Federer immediately and went up 3-0. Even at 5-2 it was hard to believe that Federer was going to lose to this up and comer, but the young Argentinian was able to close it out.
 
“I felt like today I was much more in control,” Federer said. “You know, I had many more chances. It's one of those finals maybe I look back and have some regrets about it. But, you know, you can't have them all and can't always play your best. He hung in there and did well. In the end, he was just too tough. Just the way it is.”
 
For Del Potro, winning his first Grand Slam is a dream come true. As he fell to the ground, the tears rushed from his face. Even in his post-match press conference, he had to choke back the tears.
 
“Well, when I lay down to the floor, many things come to my mind,” Del Potro said. “First my family, and my friends and everything. I don't know how I can explain it, because it's my dream. My dream is done. It's over. I will go home with a trophy, and it's my best sensation ever in my life.
 
“It's too early to explain, maybe tomorrow, maybe next week I will be believing in this. But now, I don't know. I don't understand nothing.”
 
Right now, he may not know what he did, but it will sink in. In a few days or even weeks, Del Potro will realize he went through one of the classic finals for a classic US Open.