del Potro must know what Andy Roddick felt like when he faced Roger Federer in the finals of Wimbledon in 2009.  Roddick had not been broken all day long, but at 14-15, he finally cracked and lost serve and with it, his best opportunity at winning a second Slam.

del Potro has lost to Nadal earlier this year at Indian Wells 4 and 4.  He was injured and didn’t play Rafa in the Madrid round of 16 this year.

At 6-5, Nadal seemed to do something to his heel.  It didn’t look serious in replay, but the agony in Nadal’s face suggested otherwise.  Nadal was contemplating having to retire.  Nadal got his heel taped up, but immediately fell 3-0 back in the tiebreak.  Despite del Potro’s attempts to move Nadal around and aggravate the injury, the tape seemed to help and miraculously, Nadal won the tiebreak.

In the second set, Nadal still struggled a bit with consistency and del Potro managed to break and take the second set, 6-3.  It was then del Potro who looked like he was in trouble when he slipped and appeared to injure his hip.  After an injury time out, he was ready to play again.  The third set also went to a tiebreak which Nadal won.

Finally, Nadal secured his only break early in the fourth set, and rode that break to the victory.

Last year’s finalist, Tomas Berdych had no answers to Mardy Fish who served well and eliminated the Czech in straight sets.  Fish plays Rafa in the quarterfinals.  He has never beaten Rafa in 5 attempts.  His best chance, alas, is for Rafa’s foot injury to affect him in the quarters.

Roger Federer was pushed to four sets when the apparent lead he had in the tiebreak evaporated.  However, he had three comfortable sets to reach his 29th straight Slam quarterfinal.  Jo-Wilfried Tsonga’s power proved too much for the diminutive Spaniard, David Ferrer, as he won in straight sets.  Federer will play Tsonga in the quarterfinals.

Murray plays Feliciano Lopez next.  Fans will be curious whether Mother Judy will tweet about “Deliciano” or not.  Lopez needed 5 sets to beat Kubot who qualified and used a net charging tactic to take two sets from the lefty Spaniard.

Bernard Tomic will play Novak Djokovic.  Tomic has trained with Djokovic before.  Can Tomic do the unthinkable and knock off the world number 2?  The answer is, probably not.

The men all take tomorrow off, and resume play on Wednesday.