World No. 1 Roger Federer of Switzerland is into the semifinals for the men’s singles tennis tournament at the 2012 London Olympics. In that semifinal Federer will face Juan Martin del Potro of Argentina with the winner moving on to the gold medal match and the loser playing for bronze.

Following Federer’s title at Wimbledon in July, most fully expected him to make a run at the Olympics at least as deep as he has gone so far. With del Potro, the result cannot be called a big surprise. It is, however, the first time the Argentine has turned in an impressive tournament on grass.

While Delpo has impressive results on clay and especially on the hard court surface, his results at the All England Club have typically been disappointing. This year’s run to Wimbledon’s fourth round matched his career best achievement from 2011 but the result was one or two rounds short of where many expected him to be.

Federer is into the semifinals having dropped just one set in the entire tournament. In his quarterfinal, the World No. 1 defeated hard serving John Isner in straight sets with previous victories in London coming at the expense of Denis Istomin, Julien Benneteau, and lefty Alejandro Falla.

Del Potro has victories in London over Ivan Dodig, an improving Andreas Seppi, Gilles Simon, and fourth seeded David Ferrer. The win over Ferrer was a significant win in del Potro’s career as the Argentine had fallen to the Spaniard at the recently completed grass court slam. The victory marked the first time that del Potro beat a Top 15 player at the All England Club, this suggests that he is playing better on grass now than he has in the past.

Federer and del Potro have met 14 times in their careers with Federer taking victory away in a dozen of those matches. It is important to note that del Potro has defeated Federer in a bigger match than the one they will play on Friday (noon BST). It was the Argentine that stopped Federer’s reign as the US Open champion back in 2009 with a five-set win in the final.

What is more important to note is that del Potro earned both of his career wins over Federer before the Argentine's wrist injury cost him most of his season in 2010. Since returning to tour in 2011, del Potra has lost six straight to Federer, with five of them being straight set losses.

The competitiveness of their last meeting should be noted as del Potro took two sets off of Federer in the Roland Garros quarterfinals. However that was on clay and the London Olympics are being played on grass and Federer is arguably the greatest grass courter ever.

Federer has won so many tournaments at the All England Club while del Potro has won so few matches at the venue for a top player on tour that the Argentine has to be considered a huge underdog in the match. Even at 9/2 with bet365, Delpo’s odds might be considered too short heading into Day 7 from London.