Shelton's 4hr 28min quarter-final defeat of Alcaraz wrapped up at 3:34 am on Wednesday - the latest finish in the 145-year history of the US Open.
While late-night finishes at Flushing Meadows are nothing new - in 2022 Alcaraz himself battled Jannik Sinner until 2:50 am in the previous latest finish - this year's tournament has reached new levels.
So far there have been four finishes which stretched past 2:00 am, while other sessions have seen players on court past 1:00 am.
Shelton and Alcaraz's late-night thriller didn't get underway until after 11:00 pm on Tuesday, while Venus Williams' first-round loss to Sofia Kenin did not start until after midnight, eventually wrapping up at just after 2:00 am.
Writing in response to a post on X on Tuesday, US tennis great Martina Navratilova suggested the scheduling had reached a tipping point.
Talking about the scheduling earlier in the tournament, Navratilova suggested the US Open should limit the evening session to either one men's or women's singles match, in addition to a doubles tie.
At the moment, the US Open typically places both a men's and women's singles clash on Ashe during its primetime night session.
That, though, is fraught with risk if either of the two matches goes the distance.
"I think they need to fix the night session. It's too late," said Navratilova. "I think they should play men's singles and then maybe a doubles match.
"If you do women's singles you can still have another doubles match, or another women's singles. You'll still get four sets of play minimum.
"Even if you put the women's match on first and it's three sets, the guys start by 10pm. If a men's match goes five sets, you start at midnight.
"You're never on the court at midnight, and you never start a match at midnight, so it's counterproductive for everybody, spectators and the players."
Former British tennis star Tim Henman, working at the US Open as an analyst for Sky Sports, believes that while the famously raucous night sessions in New York are an integral part of the tournament, a provision could be introduced to move matches to another court if they have not started by a certain time.
"It's hard. It is not ideal as a professional athlete when you're playing at that time, but if you look at it from a tournament's point of view, it's a massive part of their business model to have those two sessions, to sell, you know, tickets here on Ashe," Henman reflected.
"So, for me, we need night sessions; they're iconic for this event. But also, I think there should be sort of almost protected start times.
"If you have a women's match first, and if the men's match hasn't gone on by 9:30, or 10 o'clock, then vice versa, if the men's match goes first, if that is going to be a long four, five-setter, then perhaps the women's match moves elsewhere," Henman added.
Some commentators, though, have floated an even more dramatic solution: reduce the length of tennis matches by slashing the number of sets.
"I've watched tennis my whole life. I've played tennis; I love tennis. Tennis matches are too long," popular American sports podcaster Bill Simmons said.
"All the tennis purists are going to be like, 'That's crazy'...But I think they should seriously think about changing the sets from six (games) to five to win the set."
Those comments came after Andrew Abdo, the chief executive of the organizing body that runs the Australian Open, suggested Grand Slams may eventually explore reducing men's early round matches to best-of-three sets instead of best-of-five.
But US Open semi-finalist Frances Tiafoe is adamant five-setters should remain.
"Do I love five-setters? Absolutely not," Tiafoe said. "But it's tennis, man.
"I grew up watching so many incredible five-setters. Novak-Rafa, Federer-Rafa, epic five-setters that go on for hours and hours. That's the history of the game."
