Damir Dzumhur made a winning return to the St. Petersburg Open on Tuesday, recovering from a slow start to defeat Lucas Miedler of Austria 7-5, 6-3.

Having captured his first tour-level title at the event in 2017, the sixth seed struggled in the opening stages of his title defence. Dzumhur trailed Miedler by a double break in the first set, but rallied well to extend his unbeaten streak in the Russian city to six matches.

The defending champion converted five of nine break-point opportunities and won 70 per cent of first-serve points to advance after 84 minutes. St. Petersburg debutant Miedler was seeking his first ATP World Tour victory after straight-sets wins over Viktor Troicki and Uladzimir Ignatik in qualifying.

Dzumhur, who achieved a career-high No. 23 ATP Ranking on 2 July, will meet Ilya Ivashka or Guido Pella for a spot in the quarter-finals. The 26-year-old is yet to meet either potential opponent at tour-level.

Eighth-seeded Russian Daniil Medvedev needed only 67 minutes to defeat Joao Sousa 6-4, 6-1. The two-time tour-level titlist was clinical in important moments, converting each of his four break-point chances, to score his 30th match win in 49 tour-level contests this season. Medvedev will meet Mikhail Kukushkin or Denis Istomin in the second round.

Jan-Lennard Struff also enjoyed further success in St. Petersburg, beating #NextGenATP Russian Andrey Rublev 6-4, 7-6(6). The 2017 semi-finalist notched his fourth win in six matches at the event after 68 minutes, landing 18 aces in a strong serving performance.

Struff did not face a single break point throughout the first-round encounter, winning 88 per cent of points behind his first serve. The World No. 50 will face top seed Dominic Thiem in the second round.

Gstaad champion Matteo Berrettini took just under two hours to overcome 2013 finalist Guillermo Garcia-Lopez 7-6(5), 2-6, 6-3. The 22-year-old converted his only break point of the match in the decider to progress, improving to 17-15 at tour-level this season. The Italian awaits #NextGenATP Canadian Denis Shapovalov or Adrian Menendez-Maceiras in the second round.

Dominic Thiem and Karen Khachanov took a tour of St. Petersburg on Tuesday morning, cruising through the canals and out onto the Neva river to see the sights of the city.

“We had a really nice boat ride, in amazing company this morning,” said Thiem, who will play Andrey Rublev or Jan-Lennard Struff in the second round.

The Austrian also explained how he is ready to step up his bid for a third straight qualification at the Nitto ATP Finals, to be held at The O2 in London from 11-18 November.

“I have thought about the Race all year long,” said Thiem, who is currently in eighth position in the ATP Race To London. “Of course, I want to make it, as it’s the nicest tournament for players all year. I’d like to be in the Top 8.

“The US Open was great and I flew home with a great feeling, which I didn’t have the past two years. I am in good shape and I’m really looking forward to the tournament, the Asian swing, Vienna then the end of the season.

Meanwhile, Khachanov, who will face former World No. 3 Stan Wawrinka in the second round on Wednesday, is happy to be playing in his home country.

“It feels great to be back in St. Petersburg, my home in Russia,” said Khachanov. “It’s nice to play in front of home crowds, even if I do feel extra nerves and pressure. I try to deal with it as motivation. I’m really happy to be at a career-high No. 24 and it shows my hard work has paid off, I’m progressing. We’re focused on the work we have to do.”

Former and current ATP World Tour players helped NBA star Dirk Nowitzki raise money for his self-named foundation over the weekend. Nowitzki, who plays for the NBA’s Dallas Mavericks, hosted the third edition of the Dirk Nowitzki Pro Celebrity Tennis Classic on Saturday at Southern Methodist University in Dallas.

Former greats Andy Roddick, Tommy Haas, Taylor Dent and Mark Knowles, along with current player Mitchell Krueger, who recently qualified for the US Open, helped Nowitzki, along with teammates Devin Harris and Dwight Powell and former Maverick Monta Ellis, raise money for the Nowitzki foundation’s children charities. Former ATP pros David Martin and Andrew Painter along with pro wakeboarder Steel Lafferty also participated in the event.

Former World No. 1 Roddick, who lives about 315 kilometres south in Austin, played in the event for the third time and was happy to help Nowitzki, who played tennis as a boy growing up in Germany but eventually focused on basketball and is set to begin his 21^st season with the Mavericks.

“He’s been so generous with my foundation down in Austin in giving an auction item and making people feel really special being his guest at a Mavs game,” Roddick said. “This is a way that I can try to repay his generosity in what he’s doing in leading the way here in Dallas.

“I really hope Dallas realises what they have with him. Culture gets set from the top, and he’s one of the icons of Dallas sports.”

Rumour has it that Nowitzki and fellow German Haas, who announced his retirement in March in Indian Wells, played each other back in the day, during a 12-and-under or 14-and-under competition.

“I don’t remember that, unfortunately, but it’ll be great if somebody can find actually a picture if it exists somewhere of both of us being out there on the court,” Haas said. “We’re both the same age, we both turned 40 this year. He’s still doing it, I just recently retired on tour, so there’s a lot of similarities here and there. But all respect goes to him on and off the court.”

Haas, the BNP Paribas Open tournament director, said it’s a privilege to assist his countryman.

“Obviously it’s great to see what Dirk has done on and off the court, and obviously I love following his career,” Haas said. “One of the greatest players of all-time coming from Germany, it’s pretty incredible.

“So I’m very happy and honoured to know him as a friend and to be invited back here and seeing all the great work he’s doing also off the court helping families, helping kids. It’s fun to see some familiar faces here playing a little tennis for a good cause. How can you say ‘no’ to that?”

Dent, who reached No. 21 in the ATP Rankings, recently moved to nearby Keller and was also honoured to participate in the event.

“It’s always fun to get out here and compete and have a good time for such a great cause,” he said. “Dirk and [wife] Jessica [Olsson], I got to see their video last night and just a glimpse of what they do.

“They’re really pouring their hearts and souls back into the communities, so it’s an honour for me to be a part of it. You can tell with his personality he takes a lot of grief from everybody, but takes it so well. He really seems like a very humble and a very genuine person.”

Knowles and partner Camelia Georgiana Marta beat Krueger and Olsson 10-5 in the doubles finals. Marta was named the No. 1 amateur player and Krueger the top celebrity player.

“The turnout was great,” Dirk Nowitzki said. “Everybody is having fun, a lot of celebs flew in town again to support, so we’re excited.”