Perhaps that was a product of the fascination with the out-of-nowhere Shelton: Just 20 and less than a year after winning an NCAA title at Florida, he was traveling outside the United States for the first time and participating in his second Grand Slam tournament.
So the loud shouts heard most often emanating from the Rod Laver Arena stands Wednesday, under the sun that carried the temperature to 87 degrees, were for one of the pair: "Let's go, Benny! Let's go!" or "Go, Gators!"
"He had a pretty good trip," Paul noted.
Paul's story is a pretty good one, too, and it is the one that will keep going at Melbourne Park. The 25-year-old was a star in the juniors and now is making good on that promise in the pros, using a 7-6 (6), 6-3, 5-7, 6-4 victory over Shelton to reach his first Grand Slam semifinal in his 14th appearance at a major.
"Every junior to pro has a different path. ... Mine has been, like, the slowest," the 35th-ranked Paul said, mentioning a group of Americans he grew up with: Taylor Fritz, Frances Tiafoe and Reilly Opelka. "I like to think the last four years of my career has just been like steady steps moving up. I mean, that's what it's felt like. I feel like hopefully 2023 is the year where I really make a big jump."
As a bonus, Paul's mother was in the crowd for the biggest victory of his career. Paul said his mom booked a flight after he won his fourth-round match then went straight from work to the airport to make the long journey from the U.S.
"She's done a lot for me, from when I was really young until now. She's sacrificed a ton to get me here," Paul said. "She deserves to be here and deserves to see me win big matches."
Paul's next opponent will be 21-time Grand Slam singles champion Novak Djokovic, who overwhelmed No. 5 seed Andrey Rublev 6-1, 6-2, 6-4. After dealing with a worrisome left hamstring in his first two matches, Djokovic has been on quite a roll: He has won his past 11 sets and dropped a total of 27 games in that span as he chases a 10th championship in Melbourne.
Those wins are giving Djokovic confidence entering the semifinals, a round in which he has never lost at the Australian Open.
"Last two matches, playing against two guys that are really good players, in-form players, to beat them dominantly in three sets is something that is definitely something that I want in this moment, something that sends a message to all my opponents remaining in the draw," Djokovic said. "With this kind of game, of course the confidence level rises."
After dropping Rublev's record in major quarterfinals to 0-7 and extending his own winning streak at the Australian Open to 26 matches, equaling Andre Agassi for the longest run there in the Open era, Djokovic looked ahead to facing Paul for the first time.
"I know how he plays. ... He's been around for a few years. I watched him play quite a bit, especially during this tournament. He's been playing probably tennis of his life," Djokovic said. "Very explosive, very dynamic player."
The other men's semifinal Friday is Stefanos Tsitsipas against Karen Khachanov. The women's semifinals Thursday (3:30 a.m. ET) will be Victoria Azarenka vs. Elena Rybakina and Aryna Sabalenka vs. Magda Linette.
Paul initially broke through as a teenager, taking the 2015 junior title at the French Open (beating Fritz) and getting to the final at Flushing Meadows that year too (losing to Fritz). Since turning professional, he has claimed one tour-level trophy, at Stockholm in 2021, and, until this week, had made it as far as the fourth round at just one Grand Slam tournament -- at Wimbledon a year ago.
Now Paul is the first man from his country to make it to the final four at Melbourne Park since Andy Roddick in 2009. Roddick was also the last man from the U.S. to win a Grand Slam singles championship, at the US Open 20 years ago.
While Shelton was sort of adopted by the locals -- "The crowds have been pretty unbelievable. ... They kind of treated me like one of their own," he observed -- Paul was not drawing the same amount of adoration.
"I've been on the outside courts, grinding, until the round of 16," Paul said. "I've been flying under the radar a little bit."
Based purely on ranking, Paul offered a much sterner test than anyone Shelton had faced in Australia: His prior opponents were ranked 67th, 96th, 113th and 154th.
In the first Grand Slam quarterfinal between two American men since 2007, when Roddick beat Mardy Fish in Melbourne, Paul generally was content to block back the big lefty serves that kept coming from Shelton then do what he could to get the better of back-and-forths.
Paul was more steady than spectacular, limiting his miscues with compact swings off both wings.
"Extremely solid from the baseline," Shelton said. "He did a great job moving me around the court, keeping me off balance."
They shared a light moment when Paul's coach, Brad Stine, told him to look for a serve down the "T" on the ad side of the court. Shelton noticed the exchange and kicked his serve wide, leaving Paul out of position and with no chance at reaching the ace. Both players smiled.
Shelton broke twice late in the third to steal that set and yelled, "Yeah!" as he raised his left fist then pointed to his ear with his right index finger, as if telling the crowd, "Let me hear you!"
Maybe Shelton relaxed a bit there, because he started the next set poorly, double-faulting twice in a row and then missing a backhand to gift-wrap a break for Paul.
Soon enough, it was Paul letting out a scream of delight -- "Let's go!" -- after the last point, then meeting Shelton at the net for a warm hug.
ESPN's Matt Walsh and The Associated Press contributed to this report.