NEW YORK -- When tennis historians look back at the period from the 2005 French Open to the present, they will probably double-take at the record books.
During that time, there have been 34 Grand Slam champions. Roger Federer, Rafael Nadal, Novak Djokovic or Andy Murray have won 33 of those titles.
Only one man has broken through the Big Four's membrane: Juan Martin del Potro.
At the 2009 U.S. Open, Roger Federer appeared to be on cruise control. After winning five straight championships in Flushing, the No. 1 overall seed dropped only two sets in his first six matches.
Fellow finalist Del Potro too had only lost two sets in his first six matches, but his run received limited scrutiny. At this point, Djokovic, with the 2008 Australian Open championship, was the only man not named Federer or Nadal to win a Grand Slam since the 2005 French Open.
The thought of the sixth-seeded Argentine who had never reached a Grand Slam final winning the U.S. Open seemed ludicrous. Even after del Potro beat No. 3 seed Nadal 6-2, 6-2, 6-2 in the semifinals, the title of champion was viewed as a long shot.
Federer won the first set and del Potro the second in a tiebreaker. Federer won the third set and the fourth set went to a tiebreaker.
When his moment came, del Potro snatched it. He won the tiebreaker 7-4.
Rallying behind a crowd that all of a sudden adopted the then 20-year-old, del Potro pulled away for a 6-2 victory in the fifth set.
Just like that, Federer's five-year U.S. Open championship streak was snapped.
By January, del Potro reached a career high ranking of No. 4in the world. As a 21-year-old, he was set to be the rival to Federer and Nadal the world had been waiting for.
Then disaster struck. A wrist injury sidelined del Potro for the first half of 2010. Halfway through the year, he opted to surgery to repair the injury and sat out for an extended period of time.
Del Potro struggled in the first few matches of his return in 2011. He dropped all the way down to No. 485 in the world rankings.
Again, with expectations low, del Potro played his best. He reached the third round at the French Open and the fourth round at Wimbledon. By the U.S. Open he was the 18th seed.
In 2012, del Potro reached three Grand Slam quarterfinals. At Wimbledon this summer, del Potro reached his first semifinal since the 2009 U.S. Open, losing a five-set classic to Djokovic.
Despite the loss, del Potro sent a message: He's made it back. The Big Four has not had a challenger since Del Potro in 2009. Well, it is time for déjà vu.
Del Potro, seeded sixth as in 2009, opened his fortnight with a 6-3, 6-7, 6-4, 7-6 (9-7) win over Spain's Guillermo Garcia-Lopez Wednesday night. After the match, he looked calm in front of the media.
After all, he has been a champion before.
And he thinks he can be a champion again.
"I was close to it in Wimbledon, but you have really good guys playing much better than me at the moment," he said. "They are so good. That's the truth you know."
Del Potro looked damn good, as well, Wednesday night. He laced 52 winners in a workman's like victory. Garcia-Lopez challenged del Potro, but he kept answering. Eventually, del Potro's consistency fended off Garcia-Lopez's fight.
Battling day in, day out for four years, del Potro knows he can get to the top of the sport again. He is just not sure if that time is this tournament.
"I'm trying to get closer to them in these kinds of tournaments, but it's not easy," he said of the top players. "It's a long tournament. I just finished after four and a half hours."
Star or not, del Potro is miles away from where he was as the No. 485 player in the world two and a half years ago. He may not be in 2009 form, but he is where he wants to be.
"I'm glad with my level at this moment. I'm six in the world," he said. " I think I'm getting closer to the top guys, reaching the semifinals in Grand Slams, playing semifinals in the 1000 Masters. That's what I want, just go as far as I can in these kind of tournaments and play the last day against the top guys."
-- Follow Jeffrey Eisenband on Twitter @JeffEisenband.