Flushing Meadows, NY (My Sportsbook) - Argentine slugger Juan Martin del Potro shocked five-time defending champion Roger Federer in five sets on Monday to capture the title at the U.S. Open, the final Grand Slam event of the year.

Appearing in his first-ever Grand Slam final, the sixth-seeded del Potro stunned the world No. 1 Federer in a grueling five-set affair, 3-6, 7-6 (7-5), 4-6, 7-6 (7-4), 6-2 at Arthur Ashe Stadium. The 20-year-old del Potro earned $1.6 million for winning the U.S. Open and an additional $250,000 for finishing third in the U.S. Open Series. He also received a Lexus IS convertible automobile.

Federer settled for $800,000 in defeat.

The 20-year-old Del Potro, who throttled former world No. 1 Rafael Nadal in the semifinals here on Sunday, is the first Argentine U.S. Open winner since the great Guillermo Vilas turned the trick, on clay, at Forest Hills back in 1977. He's also the first player to beat both Federer and Nadal in the same Grand Slam event.

"It's amazing for South America and especially for me," said del Potro. "I think this has been in my mind, forever in my life. I don't have words to explain it."

"I had two dreams with this U.S. Open. This is one of them," del Potro added. "The other one is to play like Roger. One is done, but I need to improve a lot."

The 28-year-old Federer was trying to add to his men's record with a 16th Grand Slam title, but it wasn't meant to be. The Swiss great fell to 15-6 in his career major finals and this was the first time he lost to someone not named Nadal in such a final.

The last time Federer lost at the U.S. Open was against another Argentine, David Nalbandian, six years ago.

Federer was trying to become the first man since "Rocket" Rod Laver in 1969 to win three straight major titles in one year. The super Swiss captured the French Open and Wimbledon.

In the fifth and deciding set on Monday, del Potro broke Federer for a 2-0 lead by striking a crosscourt forehand winner, just one of many he swatted on Day 15 of the fortnight.

Federer had chance to get the break back in the next game, but the Swiss blew a break-point chance, as "Delpo" held on for a 3-0 advantage.

Five games later, del Potro broke Federer on his third championship point when one final Federer backhand sailed long. Federer saved a pair of championship points when del Potro launched a forehand wide to cap a 17-shot rally and the Argentine netted a backhand return, respectively.

In the first set on Monday, the amazing Federer broke a tight del Potro with a beautiful running crosscourt forehand winner in the Argentine's first service game, for a 2-0 lead. The Swiss icon promptly cruised to the first-set finish line after that.

In the second set, Federer came right out of the chute with a break and appeared on his way to claiming the stanza. But del Potro had other ideas.

The Argentine finally got the break back nine games later when he ripped a gorgeous forehand winner down the line to pull even at 5-all, as Federer was serving for the set at 5-4, 30-love.

Del Potro won the second-set via tiebreak on his third set point with a nifty crosscourt forehand winner. The Argentine blew a pair of set points by misfiring long with an overhead and missing long on a forehand return.

In the third set, del Potro appeared to shift the match in his favor with a huge break for a 4-3 edge, but he was unable to consolidate, as Federer broke right back to level the stanza at 4-4.

Two games later, Federer got himself a set point and converted on it when del Potro dialed up an untimely second straight double fault.

In the fourth set, del Potro broke for a 3-2 lead and held for a 4-2 advantage, as the sixth game featured a brilliant 21-shot rally, which was won by the Argentine when he drove in a tremendous forehand winner.

But Federer was able to get the break back two games later when del Potro netted a forehand.

The fourth set would eventually go to a tiebreak, which saw the Argentine prevail when Federer missed wide with a loose forehand.

Del Potro, who will turn 21 next week, pulled off the stunner in 4 hours, 6 minutes, with the help of 11 double faults from Federer, who struggled with his service game throughout the match. Del Potro piled up 60 unforced errors, but Federer tallied two more en route to the stunning setback.

Both players recorded five service breaks apiece.

The match was staged on Monday after inclement weather wreaked havoc on the schedule here Friday and Saturday.

The last U.S. Open men's final to go five sets was 10 years ago, when Andre Agassi outlasted fellow American Todd Martin for the title.

The 6-foot-6 del Potro is now 1-6 lifetime against Federer, who snuck past the tall South American in five sets in a French Open semifinal back in June.

Federer had won his last 40 matches at the U.S. Open and beaten five different players in the previous five finals here.

The classy Swiss has appeared in 17 of the last 18 major finals, winning 11.

"Of course I would have loved to win, but I had an unbelievable run here," said Federer. "I would have never thought, five or six years ago I would have won 40 matches in a row here. It's been an amazing run for me."

Del Potro is now 7-2 in only nine career finals, including three titles in four finals this season on the ATP World Tour.

Federer, who became a husband and father of twin girls and secured a career Grand Slam earlier this year, beat Brit Andy Murray in last year's U.S. Open title bout, which was also played on a Monday due to some weather problems in the Big Apple.

The Basel native Federer dropped to 61-23 in his career finals, including a 3-2 mark this year. He lost to Nadal in February's Australian Open finale.