!Gilles_488b By Rosangel Valenti, TW Contributing Editor

Good afternoon. This is today's thread for discussing the tennis in Madrid and Zurich. As always, please stick to talking about tennis until the day's action is over. Afterwards it's OK to drift off-topic.

Picture of the Day

This one features Gilles Simon celebrating his eventual victory over Robby Ginepri, in a long match that involved him dropping his serve when he was due to serve out the final set, meaning that it was resolved in a tiebreaker. The match had such meandering progress that I was able to photograph part of the first set, leave to record an hours' worth of pictures of Nadal practising, and come back to see the final stages.

Matches of the Day

We're in the quarterfinals stages now, so there are just four matches today. Currently Andy Murray leads Gael Monfils by a set.

The second match features Roger Federer versus one of the current form players of the tour, Juan Martin Del Potro - whose recent winning record has been accompanied by his ascent into the Top 10, and the strong possibility of his booking a place in Shanghai. His disposal of David Nalbandian yesterday was brutal in its efficiency. Del Potro has faced Federer twice before. He has recorded wins over other top 10 players in recent nonths - Ferrer, Davydenko and Roddick - but has yet to defeat others in the Top 10.

Today's evening session features Rafael Nadal versus Feliciano Lopez, followed by Ivo Karlovic taking on Gilles Simon. Nadal is 3-1 agaoinst Lopez, having lost to him once five years ago, on indoor carpet; the other three matches took place on clay, and were straight-sets affairs. Nadal is trying to secure the year-end number one ranking, and can do so this week if he reaches the final, so he will be highly motivated. In terms of main tour matches, Karlovic is 1-0 against Simon - they met in Nottingham last year; unsurprisingly, the three-setter they played involved two tiebreakers.

Player of the Day

This goes to Ivo Karlovic, after defeating Novak Djokovic in two straight tiebreaker sets.

Enjoy the rest of today's tennis.