It wasn’t until Taylor Fritz closed out his fourth consecutive tiebreak against a top player that he was actually in physical danger.

No, it wasn’t a tender hamstring or a sore serving shoulder -- it was Team USA teammate Frances Tiafoe, who had gleefully launched himself right at his head. The replay showed there was something more than incidental contact, but despite winding up underneath a pile of celebrating American tennis players, we can report that Fritz’ prognosis for recovery is good.

“Team events are always so much more fun when you win, because it’s so much more,” Fritz told reporters later. “It’s just so much more exciting, there’s so much more emotions. You can celebrate with your whole team as opposed to just celebrating by yourself. It was great.

“As soon as I won, I turned to the team and I knew everyone was going to run at me. It was great until Frances full speed headbutted me in the face.”

U.S. clinches United Cup title with win vs. Italy

Said Tiafoe, “I’m still a bit concussed, to be fair. The champs are here.”

Indeed they are. After singles wins earlier from Tiafoe and Jessica Pegula, Fritz locked down the inaugural United Cup for the Americans over Italy at Ken Rosewall Arena in Sydney. Madison Keys finished it off, and Team USA was a 4-0 winner.

“We’ve had a really great eternity in Sydney,” Pegula said. “It’s been really fun though. We have been bonding a lot, I feel like getting to know each other a lot. It was a good team from the start.

“I did not think I’d be doing escape rooms with these people. That was not my first thought coming into this.”

Tennis, of course, is an individual sport. Problem-solving, without the aid of teammates, can be a lonely business. In the mixed format of the United Cup, it took a village -- and the beauty of teamwork in action was breathtaking to behold.

With the exception of that headbutt.

“I had a blast these two weeks,” U.S. captain David Witt said at the joint press conference. “You guys are so immature, and I love you for it. I feel like I’m at home with my eight kids. This is like the Brady Bunch on something.

“It’s crazy. It was fun. What a family.”

The synergy was undeniable. Team USA won 18 of its 20 singles matches. The closest tie was 4-1.

Italy, which advanced to the semifinals despite losing to Poland in the Brisbane City Finals, has a promising future with a number of young players coming up. Team Italy Captain Vincenzo Santopadre thinks they will benefit from the comradery created in Australia.

“They are smiling all the time,” he said of Martina Trevisan and Lucia Bronzetti. “I like this. I think that also men, we are doing some nice things. I think all the Italian players that are coming will have to thanks these guys -- there are so many young [players] coming, it’s because of them.

“I think everybody is doing things with passion, and then you can see the results.”

Here are a handful of other takeaways from 11 days of United Cup action:

The capacity for surprise: Rafael Nadal, a 22-time Grand Slam champion, failed to win a match in Sydney. Cam Norrie of Great Britain and Alex de Minaur of the hosting Australia summoned inspired efforts. World No.1 Iga Swiatek was surprised by No.3 Pegula.

The power of two: The United States’ second singles players won all 10 of their matches. Keys, ranked No.11, and Tiafoe, No.19, played behind No.3 Pegula and No.9 Fritz. In all, 12 of the 17 of the teams winning ties swept second singles. Only one tie featured a team (Greece) that managed to win despite losing both second singles matches.

Speaking of Greece: On a loaded team that featured No.4-ranked Stefanos Tsitsipas and No.6 Maria Sakkari, it was another Stefanos -- Stefanos Sakellaridis -- who provided the most memorable moment. The 18-year-old, playing his first ATP Tour-level match, defeated Zizou Bergs (ranked No.129) of Belgium. Sakellaridis is ranked No.630. “We all experienced something phenomenal -- isn’t that right?” Greek Captain Petros Tsitsipas said at the team’s post-match press conference. “No expectations, and he managed to pull out his first ATP win, which is amazing. So he has 100 percent record. I don’t think many guys on the tour have this record. You probably are the only one.”

Every set matters: Croatia’s Borna Coric, Donna Vekic, Borna Gojo and Petra Martic went 2-0 to win Group F, over France and Argentina, but fell to Greece 3-2 in the Perth City Final. That left Croatia and Italy as the candidates for the fourth and final spot in the Sydney semifinals. Both teams won 21 sets in three ties, but Italy lost one fewer (12 to 13) and advanced.

Mixed and matched: Mixed doubles proved to be a big hit. Swiatek and Hubert Hurkacz , a pair of Top 10 singles players, formed a formidable partnership. So did Tsitsipas and Sakkari. But it was Isabella Shinikova and Alexandar Lazarov of Bulgaria who scored the first clinching point for mixed doubles -- against Elise Mertens, the WTA Finals doubles titlist, and David Goffin.