After both the men's and women's No. 4 players tumbled from the tournament field on Monday, the message at Indian Wells is clearly that no one is safe, no matter their ranking.
It's hard to guess what will take place on Day Seven, but one thing's for sure: These are the matches to watch as the men conclude their third round, and the women begin the round of 16.
Andy Roddick (USA) vs. John Isner (USA) - It could be billed as the present vs. the future of American men's tennis, until you remember that Roddick is just three years older than Isner. That's what happened when one guy turns pro at 18, and the other after a college career.
Isner has started 2011 in unimpressive fashion, dropping to 33rd in the rankings and the 30th seed here, but his massive serve always makes him dangerous.
Roddick won Memphis three weeks ago, his 30th ATP title, and whipped James Blake two days ago. Roddick owns a 2-1 series lead, but Isner won their last meeting, a five-set marathon at the 2009 US Open.
Ryan Harrison (USA) vs. Milos Raonic (CAN) - It's an old-fashioned border war between two guys who never saw the 1980s.
The 18-year-old Harrison, who is the older of two, born in December of 1990, has stunned Jeremy Chardy and 22nd-seeded Guillermo Garcia-Lopez to date. This is the deepest he's ever made it at a Masters 1000 event, and just by reaching this round, he'll move up at least 20 spots in the rankings.
Raonic has already enjoyed stunning success in 2011. His first career title and with his powerful serve and impressive return game.
Ernests Gulbis (LAT) vs.Novak Djokovic (SRB) - For being a wonder kid, Gulbis is just 13 months younger than Djokovic, and 31 spots lower in the rankings.
Djokovic will be on his guard, particularly after seeing contemporaries Andy Murray, Robin Soderling and David Ferrer, the three men ranked immediately behind him, washed out in the past six days.
Djokovic is 14-0 on the year, Gulbis is 7-5, and Djokovic leads the series 3-1.
Marin Cilic (CRO) vs. Stanislas Wawrinka (SWI) - Both are red-hot, and both ranked in the Top 20. Just another showcase of how deep this field is.
Jelena Jankovic (SRB) vs. Ana Ivanovic (SRB) - Don't expect much production from Serbian offices and factories during this match.
The country's two leading ladies, will face off for the first time since Madrid last season, when Jankovic took an easy win. Overall, it is their 10th career matchup, with Ivanovic owning a 6-3 lead. However, Jankovic is playing better overall this year, 13-5 to date, while Ivanovic is just 4-3.
It's one of two matchups today featuring a pair of former No. 1s.
Dinara Safina (RUS) vs. Maria Sharapova (RUS) - If the 7.3 million residents of Serbia are excited about their two former No. 1's facing off, imagine the TV rating in Mother Russia when a potential TV audience of 142 million tunes in to watch Safina and Sharapova square off for the first time in three seasons.
The pair have combined for 34 pro titles and more than $24 million in career earnings.
Safina, the older of the two, is still a month shy of turning 25. She soars into today's fourth round match off a colossal upset of Samantha Stosur. While Sharapova was impressive in handling Arianne Rezai in straight sets.
Their all-time series is tied 3-3, with Sharapova victorious twice on hard surfaces.
Yanina Wickmayer (BEL) vs. Dominika Cibulkova (SVK) - Both ranked in the mid to high 20s, these two ladies are a contrast in appearance. The 6-foot Wickmayer's smashing hard serves. While the 5-foot, 3-inch Cibulkova uses her speed to great advantage.
Both are 21-years-old, and eager to reach a quarterfinal.
Wickmayer beat 14th seed Kaia Kanepi. Cibulkova beat third-seeded Vera Zvonareva.
Cibulkova owns a 2-1 head-to-head advantage.
Kim Clijsters (BEL) vs. Marion Bartoli (FRA) - The world's No. 2-ranked player looked positively mortal while limping past Sara Errani in three sets two days ago. She'll have to be much sharper against Bartoli, who shredded Andrea Petkovic 6-4, 6-2 in the third round and is a potent 15-6 on the season.
Clijsters leads the all-time series 3-0.