(CNN) - Wimbledon's "Manic Monday" hardly disappoints and so it continued in 2019.
The only grand slam where all 32 players remaining in singles are scheduled to compete on the same day, there were two massive upsets in the women's draw -- world No. 1 Ashleigh Barty and Karolina Pliskova tumbled -- while Serena Williams and the men's Big Three of Roger Federer, Rafael Nadal and Novak Djokovic all cruised in the fourth round.
If Federer and Nadal win their quarterfinals Wednesday, they would meet at Wimbledon for the first time since their epic 2008 final considered by many to be the greatest tennis match ever.
Trying to stop them will be Kei Nishikori and Wimbledon giant killer Sam Querrey, respectively.
Think they don't have a chance? Well Nishikori beat 20-time grand slam winner Federer the last time they played, and Querrey upended 18-time major champion Nadal in their last duel.
But Coco Gauff's Wimbledon fairytale finally came to an end with a defeat by former world No. 1 Simona Halep.
Gauff beaten by Halep
The 15-year-old American qualifier had taken the tournament by storm after her first-round win against Venus Williams but her remarkable run was halted 6-3 6-3 by Romania's Halep.
Gauff's story had touched the tennis world, especially as she defied her inexperience to save two match points in victory against Polona Hercog in round three.
"I learned a lot," said Gauff, who revealed she was struggling with a stomach issue during the match. "I learned how to play in front of a big crowd. I learned what it was like to be under pressure. I'm really thankful for this experience."
Halep won the French Open last year and was world No.1 as recently as January before being eclipsed by Naomi Osaka and Barty. Then at Roland Garros she was upset by another US teen, the 17-year-old Amanda Anisimova.
"I feel better mentally," Halep told reporters. "I'm not tired any more. I've been a little bit tired at the beginning of the year. I'm fresh, emotional talking. I started to feel hungry of the results already.
"Every match I want to win it badly. I'm trying just to do that."
World No. 55 Alison Riske, whose previous best grand slam result was a fourth round at the 2013 US Open, said she was "proud" of herself for beating Barty 3-6 6-2 6-3.
Riske -- who has compared her dad to Robert De Niro -- could be considered a grass-court specialist. She has long enjoyed playing on grass and is now 14-1 on the surface in 2019.
"I love being at Wimbledon. Today I told my fiance, 'I don't want Wimbledon to end,'" said Riske, who wept at the end of her press conference as she reminisced about the late Paul Hutchins.
Hutchins, a former British Davis Cup player and tennis administrator, died in March aged 73.
"Paul was there from (my) first Wimbledon," said the 29-year-old. "He would always have me hit on the grass before Wimbledon started."
Barty said going out in the fourth round and seeing her 15-match winning streak end was "nothing to be sad about."
"For us it's been an incredible journey to get to this point but it hasn't changed our approach," the new French Open champion said.
"Every day I try my best and that's all I can do. Obviously it's bittersweet at the moment but nothing but positives from us."
Pliskova not very happy...
Third seed Pliskova was another highly ranked casualty after losing to fellow Czech Karolina Muchova 6-4 5-7 11-13 in three hours, 17 minutes.
Like Riske, the 68th-ranked Muchova landed in a maiden grand slam quarterfinal. But only after the big server and recent Eastbourne champion failed to serve out the contest at 5-3 in the third.
"Right now it's just a s**t day," the ever-blunt Pliskova said.
Serena storms on
Riske said she would be "ready for a war" when next challenging former doubles partner Williams on Tuesday.
The 37-year-old Williams has only played five tournaments this season because of a knee injury but insists she is fit and hungry for a first Wimbledon title since 2016.
She lost in the final to Germany's Angelique Kerber last year but one more grand slam victory would tie Margaret Court's all-time record of 24.
"I've had more matches this week than literally the last five months, and now I'm feeling better physically it's almost relief more than anything," said Williams, also competing in the mixed doubles with Andy Murray.
Britain's Johanna Konta delighted the home crowd with a 4-6 6-2 6-4 win against two-time champion Petra Kvitova. The 19th seed held her nerve after initially seeing a 5-1 lead and two match points fizzle in the decider.
Three more wins and Konta would become the first British women's winner here since Virginia Wade in 1977. Konta confronts another Czech next in Barbora Strycova, who rallied from a set and 5-2 down to overcome Elise Mertens 4-6 7-5 6-2.
Even at the age of 37, matching Williams, Federer continues to impress and captivate the tennis world.
The eight-time Wimbledon champ took just 74 minutes to stroll past Matteo Berrettini 6-1 6-2 6-2 in one of the most lopsided matches Wimbledon has ever seen. His next foe is Nishikori, who has impressively made three grand slam quarterfinals this year.
The Japanese baseliner is well rested at Wimbledon, too, after grueling runs at the Australian Open and French Open when he had to face Djokovic and Nadal, respectively.
"I'm happy to be playing Roger now because I think I'm in good shape now," said the 2014 US Open finalist.
Spain's Nadal, playing for the first time since clinching that record-extending 12th French Open title last month, made short work of frequent practice partner Joao Sousa of Portugal 6-2 6-2 6-2 as he targets a first Wimbledon final appearance since 2011.
The 33-year-old's knee problems have been a hindrance on the low-bouncing grass over the years but he has shown a new lease of life on the surface of late. He lost a five-set semifinal thriller to Djokovic last year.
Nadal warmed up for Monday by having a "very good paella" cooked by a friend on Sunday's traditional day off.
Next Nadal battles Querrey, the tournament ace leader who has already downed Wimbledon champions Djokovic and Murray in past visits to southwest London.
"When he plays well, he can be very, very dangerous on all surfaces," said Nadal.
Pella stuns Raonic
Defending champion Djokovic was also able to breeze into the next round without much trouble, knocking out Ugo Humbert 6-3 6-2 6-3. With that, the Serb set up a clash with former finalist at the year-end championships, David Goffin.
Manic Monday's last completed singles outing was a thriller, as Guido Pella rallied from two sets down to eliminate Milos Raonic 3-6 4-6 6-3 7-6 (7-3) 8-6. Raonic, who has one of the biggest ever serves in tennis, was unable to close the match out at 5-3 in the fourth.
Pella, an Argentinian lefthander enjoying a breakthrough campaign, has now ousted three past finalists at Wimbledon and at SW19 in Raonic, Kevin Anderson and Marin Cilic.
"Seriously, I never thought that I was going to do a quarterfinals in a grand slam," said the world No. 26.
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