As the Citi Open enjoyed its best weather all week on Saturday – 87-degrees Fahrenheit (30,5 degrees Celsius) with partly sunny skies and zero rain – all around, the men’s ATP 500 series event at Rock Creek Park Tennis Center in Washington, D.C., exuded a youthful feeling. By the end of the day, it suggested to everyone attending that the kids are all right.

Indeed, youth is being served in a big way and with big aspirations, too.

Stadium Court Washington (photo: Michael Dickens)

Who would have thought that World No. 3 Alexander Zverev, at age 21, would be the “adult” in the Citi Open semifinal foursome, which also included 20-year-old Andrey Rublev, and a pair of 19-year-old teens, Stefanos Tsitsipas and Alex de Minaur?

By the weekend, this year’s 50th edition of the Citi Open became a #NextGenATP gathering of future stars. It may also represent a changing of the guard in men’s tennis, too. All four of the semifinalists were 21 and under, the first time it’s happened at a tour-level tournament since 1995 at Buenos Aires.

“Veteran” Zverev beats Tsitsipas

In the featured semifinal played Saturday afternoon on Stadium court, the top-seeded Zverev moved a step closer to successfully defending his 2017 Citi Open singles title by defeating the No. 10 seed Tsitsipas, 6-2, 6-4. It was Zverev’s 40th win of the season – most of any tour player – and he accomplished the straight-set win without facing a break point against the 32nd-ranked Greek during the course of their one hour and 28 minute match before an enthusiastic crowd that cheered great play from both players.

🏆 defense on track!

Alexander Zverev produces a stunning performance, defeating Stefanos Tsitsipas 6-2 6-4 to reach the #CitiOpen final. pic.twitter.com/jWT5yPVbvv

— Tennis TV (@TennisTV) 4. August 2018

Perhaps, the biggest highlight – and the turning point of the match – came when Zverev broke Tsitsipas in the ninth game of the second set, winning a marathon 24-point game that featured nine deuce points and a diving hot shot by Tsitsipas, where he put his body on the line, diving to earn one of six game points he earned that would have made even Boris Becker proud. Soon, the German wunderkind served out the win and put away the victory on his second match-point opportunity.

“I’m the old guy this week,” joked Zverev during his post-match gathering with the media. “Being the oldest semifinalist this week shows that our Next Gen players are playing absolutely amazing tennis and they’re all on the come up and we could all do well in big tournaments. It’s great to see and hopefully this will not be the last time, but in the future this will happen more often.”

Zverev is now one win away from successfully achieving his second title defense of 2018 after he won his second straight title in Munich last May. He’s also in pursuit of his third tour-level title of the year and ninth in his young career, which includes three ATP World Tour Masters 1000 trophies.

“Winning the first time feels amazing,” said Zverev in describing his Citi Open success of a year ago, “but coming back here (there is) a little bit of pressure on your shoulders to defend your title. I’ve got another tough match ahead of me, but if I am able to (retain my title), it would be an amazing feeling.”

De Minaur rallies past Rublev

Zverev will face de Minaur, ranked 72nd, in Sunday afternoon’s final at 3 p.m. Eastern Time. The young Aussie fought off four match points during an exciting second-set tie-break that he miraculously pulled out after being down 2-6 against the 46th-ranked Rublev. Then, de Minaur went on to win his night session semifinal match over the Russian on his forth match-point opportunity, 5-7, 7-6 (6), 6-4. It took two hours and 52 minutes to decide the outcome, but it was worth every minute it took for de Minaur.

💚💛 off the charts! @alexdeminaur saves four match points and defeats Andrey Rublev 5-7 7-6(6) 6-4 in an epic battle to reach the #CitiOpen final on his debut. pic.twitter.com/to9aDa2ZAW

— Tennis TV (@TennisTV) 5. August 2018

“I never gave up; that’s what is all about,” said de Minaur, speaking with a small group of reporters minutes after his victory. “In the tie-break, I had to play some really good points. … You’re not really thinking too much. You’re just trying to fight – and fight some more. I left it all out there until the end. I’ll look back on it and not really know how I did it. Now that it’s over, I’m really happy.”

Earlier, the 16th-seeded Rublev advanced over local favorite Denis Kudla, ranked 85th, from nearby Arlington, Virginia, 6-1, 6-4, in a quarterfinal match that was rained out Friday night. It set the match up for the evening semifinal between Rublev and de Minaur, who advanced via walkover Friday over Andy Murray. The Scot pulled out of the Citi Open, citing fatigue, following his third-round win over Marius Copil that didn’t end until 3:01 Friday morning.

The Citi Open is just Rublev’s third tournament back on tour after missing three months due to a stress fracture in his lower back. He’s looked solid all week long with earlier wins over a pair of Americans, Tommy Paul and Noah Rubin. Rublev hadn’t lost a set all tournament until the second set against de Minaur.

After beating Kudla, who was the last of 12 American men standing, Rublev described in a Tennis Channel interview how much he missed playing tennis. “It was a really tough three months for me,” he said. “I wasn’t even thinking about how I’m going to play, if I would play good or bad. I was just missing being on court a lot. I was missing competing and finally I’m here, I’m in the semis and I’m really happy.”

Kuznetsova stays focused

Svetlana Kuznetsova booked her spot in the WTA International Event singles final by dominating Andrea Petkovic of Germany, 6-2, 6-2, in the afternoon session Saturday. The 33-year-old tour veteran from St. Petersburg, Russia, who is looking to boost her ranking of 128th, broke Petkovic’s serve five times in nine tries while saving three of the four break points she faced. Kuznetsova outpointed the 91st-ranked Petkovic 68-50 during their one hour and 23 minute match on Stadium court.

Earlier, Kuznetsova, who won the 2014 Citi Open title, reached the semifinals by advancing over No. 8 seed Yulia Putintseva of Kazakhstan, 6-2, 6-2, in a quarterfinal match that was suspended by Friday’s rain. Kuznetsova was ahead, 6-2, 2-2, when play resumed Saturday and she made quick work of her opponent.

“The weather I cannot change, so I’ve just tried to stay calm throughout,” said Kuznetsova during an on-court interview after winning her quarterfinal. “It’s great for me to come back to D.C. and to play well this week.”

Kuznetsova, who is yet to drop a set the entire tournament and has lost just 14 games over her four matches, will play No. 7 seed Donna Vekic of Croatia, who won her night session semifinal over Saisai Zheng of China, 7-5, 6-3.

“I’ve really tried to stay focused this week,” said Kuznetsova later during her post-match press conference. “I’m seeing the ball well.

“I didn’t expect such a good result so fast, because I haven’t been playing so well after my injury, after my surgery, so it took me some time to get back. I did some good preparation before this tournament, and I’m feeling great.”

News and noteworthy

* Stefanos Tsipsitas, ranked 32nd, is the only Greek to ever reach the Top 100 in the history of the ATP Rankings. Last month at Wimbledon, he became the first Greek to reach the round of 16 at a Grand Slam in the Open Era.

* Alex de Minaur, ranked 72nd, is one of five Aussies currently ranked in the Top 100.

* The four Citi Open semifinalists will be placed in the Top 6 in the Next Gen ATP Race to Milan on Monday. Zverev is also third in the ATP Race to London.