After the traditional Wimbledon day off Sunday, all 16 players left in the draw will duke it out Monday for the opportunity to advance to the final eight.
Ravi Ubha breaks down each matchup for one of the greatest days of the tennis season.
No. 1 Roger Federer vs. No. 20 Lleyton Hewitt
Hewitt is one of the top competitors out there and a guy who knows how to play on grass, having won the title six years ago. He has been bothered by a bad hip, however, and has lost his past 11 matches against the five-time defending champion. Even worse for the Aussie, Federer appears to have put the French Open debacle behind him, having not lost a set in three matches.
Prediction: Federer in three
No. 2 Rafael Nadal vs. No. 17 Mikhail Youzhny
When they last met, in January's Chennai Open final, Youzhny battered the world No. 2 6-0, 6-1 in less than an hour. Keep in mind, though, that Nadal had played a three-and-a-half-hour epic against mentor Carlos Moya the day before.
Nadal had won their previous three battles, including one in five sets in the fourth round at Wimbledon last year, after rallying from a two-set hole. He is, by his own admission, an improved player and is on a roll after winning his first career grass-court tournament at the Artois Championships.
Prediction: Nadal in three
No. 8 Richard Gasquet vs. No. 12 Andy Murray
Gasquet is hitting his form under new coach Guillaume Peyre. The Frenchman reached the quarterfinals of the Artois Championships this month and steamrolled a tough-looking opponent, Mardy Fish, in the first round here. He has lost only one set so far, which seems to show focus. He was losing to virtually everyone during his recent slump.
Murray has worked his way past three tricky opponents, notably Tommy Haas in the third round. He is 0-2 against Gasquet, mind you.
Prediction: Gasquet in four
No. 13 Stanislas Wawrinka vs. Marat Safin
Wawrinka looked sharp in the first three rounds, despite not playing a grass-court tune-up. He has won all eight sets he has contested, although the Swiss No. 2 benefited from a retirement by German Mischa Zverev in the third round.
While Wawrinka, 2-0 against Safin, has advanced quietly, the Russian caused the biggest men's upset so far with a second-round scalping of Novak Djokovic. Perhaps more impressive was that Safin followed it up, beating improving Italian Andreas Seppi in four tight sets.
Prediction: Safin in five
No. 10 Marcos Baghdatis vs. No. 31 Feliciano Lopez
Both have had success on grass, with the versatile Baghdatis making the quarterfinals and semifinals in his previous two Wimbledon appearances, and Lopez, armed with a huge serve, getting to the quarters three years ago. Another similarity: You never know what you're going to get from either when he walks onto the court.
Baghdatis has more weapons, and working with much-respected Swede Peter Lundgren seems to have helped -- the Cypriot reached his first quarterfinal since February last week in Halle, Germany.
Prediction: Baghdatis in four
No. 22 Fernando Verdasco vs. Mario Ancic
Ancic served huge against one of the best returners in the game, fifth-seeded David Ferrer, on Friday, not dropping serve. The bad news is that an injured Achilles tendon forced the 2004 semifinalist out of practice Saturday.
Verdasco has made a seamless transition from clay to grass, reaching the final in Nottingham last week before losing to 6-foot-10 Ivo Karlovic of Croatia. He wasn't broken in a third-round win over wandering Czech Tomas Berdych, either. Ancic downed Verdasco at the Artois Championships two weeks ago, by the way.
Prediction: Ancic in five
Janko Tipsarevic vs. Rainer Schuettler
Tispsarevic beat Andy Roddick in the second round, rallied from match point down against Fernando Gonzalez at Wimbledon last year and stretched Roger Federer to 10-8 in the fifth set at the Australian Open in January, yet the Serb still hasn't made a Grand Slam quarterfinal. (He admitted at Artois that he needs to get tougher mentally.)
Schuettler, at 32 one of the veterans on tour, knocked off grass-averse opponents in the first and third rounds, eliminating James Blake, mediocre in majors, in between.
The former world No. 5, now outside the top 90, Schuettler did well to get this far.
Prediction: Tipsarevic in four
Arnaud Clement vs. Marin Cilic
Clement entered Wimbledon ranked 145th, although three of his four top-tier victories this season came immediately preceding the tournament at a warm-up in the Netherlands. The 30-year-old's run here has put him in the fourth round of a major for the first time since the 2003 French Open.
Cilic, 19, is touted as one of the game's brightest stars. He beat another Frenchman, Paul-Henri Mathieu, in the round of 32 (the third straight week he faced Mathieu), but he lost to Clement last year in their lone meeting.
When Clement is on, he can drive inexperienced opponents nuts.
Prediction: Clement in four
No. 6 Serena Williams vs. Bethanie Mattek
Mattek got a little help in the third round when last year's finalist, Marion Bartoli, suffered a shoulder injury. The 23-year-old from Phoenix probably would have had a shot anyway, having entered Wimbledon with a 20-4 record in her past 24 matches, lower-level tourneys included.
Let's be honest, though: Bartoli is one thing; Williams is quite another.
Prediction: Williams in two
No. 4 Svetlana Kuznetsova vs. Agnieszka Radwanska
Kuznetsova suffered her usual early round wobble, losing the first set against France's Mathilde Johansson in her opener. She has pulled it together in the past two rounds, helping her forget about a woeful showing against Dinara Safina in the French Open semis.
Radwanska, a clever Pole, is 14-1 in her past 15 matches and knows how to keep the ball in play, with a little gusto to boot. Ignore that she's 1-4 against Kuznetsova.
Prediction: Radwanska in two
Could defending champion Venus Williams have asked for an easier first three rounds?
Kleybanova, 18, isn't a household name, either, although the Russian -- one of many stalking the circuit -- has climbed more than 100 spots to 47th in the rankings since January and ousted Ai Sugiyama, no stranger to grass, in the third round.
Like Serena, however, Venus usually heats up when it counts, the grass inspiring her further.
Prediction: Williams in two
Like the much older Haas, Jankovic seems to always have something physically wrong with her, the latest bad news coming when she hurt her knee against precocious Dane Caroline Wozniacki on Saturday. An MRI was ordered as a precaution.
Even if she weren't injured, Jankovic would have her hands full.
Tanasugarn, 31, won a warm-up in the Netherlands as a qualifier and has had by far her most success at a major at Wimbledon, having reached the final 16 six times.
Alas, Jankovic should gut it out.
Prediction: Jankovic in three
Chakvetadze might have destiny on her side, having staved off match points against unheralded Canadian Stephanie Dubois in the first round, while the big-hitting Vaidisova has the head-to-head edge at 2-0.
Dare we say Vaidisova is finally warming up after ending a six-match losing streak in early June and teaming up with Tim Henman's old coach, David Felgate?
Prediction: Vaidisova in two
No. 21 Nadia Petrova vs. Alla Kudryavtseva
The first thing Petrova should do Monday is think closely about what she'll wear: Kudryavtseva said one of the reasons she wanted to beat Maria Sharapova in the second round was that she didn't like her fellow Russian's attire.
Admirably, Kudryavtseva didn't suffer a letdown in the third round, although Petrova won't have a better chance to reach a Grand Slam quarterfinal for the first time since the 2006 Australian Open. Heck, there's a reason Kudryavtseva entered Wimbledon outside the top 150.
Prediction: Petrova in two
No. 5 Elena Dementieva vs. No. 24 Shahar Peer
Dementieva has been on a roll since February and, who knows, might have reached the French Open final this month if she hadn't suffered a meltdown against Dinara Safina in the quarterfinals. (Guess what? The serve had nothing to do with the meltdown.)
Peer endured a mentally and physically exhausting third-round match against Safina on Saturday, winning 8-6 in the third, the match lasting more than three hours and 20 minutes. Peer almost choked it away in the third when Safina was reduced to tears with leg cramps.
Prediction: Dementieva in two
No. 15 Agnes Szavay vs. Zheng Jie
Zheng didn't have to be spectacular in ousting world No. 1 Ana Ivanovic on Friday, although she was no slouch: The Chinese took the ball early, hit deep and pounced on the Serb's first serves. Don't pay too much attention to her ranking. She's outside the top 130 only because an ankle injury set her back last year.
Szavay has failed to live up to expectations since reaching the U.S. Open quarterfinals in 2007 and was barely above .500 before Wimbledon. She's had a cushy draw here, too.
Prediction: Zheng in three
Ravi Ubha is a frequent contributor to ESPN.com.