Kim Clijsters penned another heart-warming chapter into her riveting US Open chronicles on Tuesday to set a date with budding writer Serena Williams, while Andy Murray ran out of ideas to prolong his stay in New York.
Murray had been tipped as one of the favourites to win his first major title here but he scarcely resembled a player rated second best in the world as he yelled, screamed and shouted his way to a 7-5 6-2 6-2 last 16 defeat by Croatian Marin Cilic.
While US Davis Cup captain Patrick McEnroe commentated "we did not see this one coming," Murray said: "Today I could have been better in pretty much every part of the game, whether it was mental or serve, forehand, backhand returns. I just struggled today. I played poorly."
The Briton's abysmal performance left Cilic to face another rising 20-year-old, Juan Martin del Potro, in the quarter-finals. The Argentine sixth seed cantered to a 6-3 6-3 6-3 win over Juan Carlos Ferrero.
Ferrero's fellow Spaniard and ex-world number one Rafael Nadal looked vulnerable for one set before he ended the antics of French showman Gael Monfils 6-7 6-3 6-1 6-3.
But it was another former top-ranked player who has been providing the feel-good factor at this year's championships.
Belgian mother-of-one Clijsters, who flew into New York with more toys stashed in her suitcase than rackets, showcased her lightning court speed as she dispatched China's Li Na 6-2 6-4 to reach the semi-finals.
Next up for Clijsters, who needed a wildcard to play here as she does not even own a ranking yet, will be three-times champion Williams.
The American second seed has been doing the rounds in New York promoting her autobiography but conserved enough energy to surge past Italian world number 10 Flavia Pennetta 6-4 6-3.
Looking forward to her match with Clijsters, Williams said: "She's such a great person. I wish only the best for her but obviously not in the next match.
"Initially I was (surprised with her comeback) but a couple of weeks ago I knew she was someone to watch out for."
While many tennis fans are wondering how Clijsters -- a 26-year-old woman who has been out of action for over two years -- can create so much havoc at a grand slam, men's world number one Roger Federer had an easy explanation.
"It's like riding a bike; once you know how to ride a bike, you never forget that," said the new father of twins.
"That's why I'm not that surprised. I think it's a beautiful story. It's nice that she hasn't lost the love for the game. Going out of the game at 23, that's for me just shocking. It's nice to see her back in the game."
Federer and the fans may be delighted to see Clijsters back but her vanquished rivals are unlikely to agree.
After taking down 14th seed Marion Bartoli and world number three Venus Williams in previous rounds, Li was the latest to be on the receiving end of the Clijsters masterclass.
No longer bogged down by the litany of injuries that forced her out of the game in 2007, the 2009 incarnation of Clijsters described her amazing run to the last four as "wow."
However, just 15 months ago the thought of becoming the first mother to win a major since Evonne Goolagong in 1980 had not even entered her head.
"I felt like an elephant just trying to move. Even two steps was terrible," recalled Clijsters about her first experience with a racket following the birth of her daughter Jada.
On Monday, it was the usually fleet-footed Murray who lumbered around court.
Carrying a left wrist injury which hindered his two-handed backhand, Murray went into meltdown after failing to take two set points on the Cilic serve at 5-4 in the opening frame.
With Murray emitting a series of anguished cries of "aaargh" and "ayeeeeeee" every time he missed a shot, those walking on the National Tennis Center grounds might have thought Arthur Ashe Stadium had temporarily been turned into an ER.
Murray could have done with some medical attention but instead dropped serve at 5-5 and from then on the 16th seeded Cilic surrendered only four more games.
"I'm disappointed. I don't know how long or how quickly it will take me to get over it," said a glum Murray.
The Scot's day ended in more heartache as Nadal's victory over Monfils ensured he would snatch back the number two ranking next week.
Nadal, suffering no ill effects from the abdominal strain which had caused him some discomfort in his previous match, will face 11th seed Fernando Gonzalez. The Chilean completed a bad day for the French when he beat seventh seed Jo-Wilfried Tsonga 3-6 6-3 7-6 6-4 in a lively showdown.