The first ever meeting of Serena Williams and Venus Williams in Abu Dhabi has been called "an once in a lifetime opportunity" by Vickie Gunnarsson, the tournament director of the Mubadala World Tennis Championship (MWTC). The match-up between the American sisters is the final match on Thursday's opening day of the three-day tournament at the International Tennis Centre at Zayed Sports City, with the action due to start at 8pm. Serena is back in Abu Dhabi a year after she competed in the first women's match at the MWTC when she lost to Jelena Ostapenko, and the 23-time major winner is up against her older sibling, who has seven grand slam titles to her name. With Serena being 37 and Venus 38, Gunnarsson, who has overseen every MWTC since its inception in 2009, believes that people should enjoy the Williams sisters taking each other on while they still can with both players in the latter days of their careers. ______________ <strong>Read more:</strong> <strong>Kevin Anderson: <a href="https://www.thenational.ae/sport/tennis/kevin-anderson-i-want-to-face-rafael-nadal-and-novak-djokovic-at-mubadala-world-tennis-championship-1.806211">I want to face Rafael Nadal and Novak Djokovic at Mubadala World Tennis Championship</a></strong> <strong>MWTC: <a href="https://www.thenational.ae/sport/tennis/mubadala-world-tennis-championship-complete-player-guide-as-novak-djokovic-rafael-nadal-and-serena-williams-head-to-abu-dhabi-1.805887">Complete player guide as Novak Djokovic, Rafael Nadal and Serena Williams head to Abu Dhabi</a></strong> <strong><a href="https://www.thenational.ae/sport/tennis/dominic-thiem-aims-to-continue-great-2018-form-at-mubadala-world-tennis-championship-1.806163">Dominic Thiem aiming to continue his great form in 2018 at the Mubadala World Tennis Championship</a></strong> <strong>The Serena Williams interview: <a href="https://www.thenational.ae/sport/tennis/serena-williams-taking-on-sister-venus-is-the-ultimate-rivalry-1.805248">Taking on older sister Venus is 'the ultimate rivalry' for the champion</a></strong> <strong><a href="https://www.thenational.ae/sport/tennis/rafael-nadal-ready-to-get-best-preparation-for-2019-season-at-the-mubadala-world-tennis-championship-1.804677">Rafael Nadal ready to get 'best preparation' for 2019 season at Mubadala World Tennis Championship</a></strong> ______________ "Getting the two of them together doesn't happen that often so it is exciting times," the Swede said. "In the past they have played in Dubai and both competed there, but this is their first time here against each other. "You never know how long these guys are going to keep going so in many ways it is a once in a lifetime opportunity to see these two face off each other." The Williams sisters have played each other 30 times on the WTA Tour, with Serena leading 18-12 in terms of victories. Gunnarsson believes the success both women have had in the game makes them ideal role models for the tennis public in the UAE as well as the international audience. "Serena and Venus have done so much for the sport globally as role models, this just sits well for Abu Dhabi," she said. "I think they can inspire a lot of women by playing this match here and I am very happy it is happening this year." The men's line-up, which starts on Thursday with defending champion Kevin Anderson facing Hyeon Chung while Dominic Thiem takes on Karen Khachanov, is headlined by the top players in the world, Novak Djokovic and Rafael Nadal. The pair, who have byes to Friday's semi-finals, have won the tournament seven times in the past (Djokovic three to Nadal's record four), but Gunnarsson believes that it is vital the event still features new players. Both Khachanov and Chung are debutants, while Thiem is making only his second appearance at the competition. "I think it is always important to keep it entertaining for the fans and to bring in some new faces to the tournament," she said. "Men's tennis is going through an exciting time at present. You have Rafa and Novak still going strong on the tour, and then the young guns having the chance to come through. "I definitely think we have found a good balance, that represents the game at present for this year and I think we should have a very strong event." Playing the women's match on the opening day of the event is the latest alteration to the format for the competition, and Gunnarsson said she would assess how this year's action is received before committing to any plans for the 12th staging of the action in 2019, but remains confident it will stick to its objectives and goals. "I think this year we have gone full steam ahead with this new format, and we will see what we do next year but I am definitely very excited for the tournament's future," he said. "The whole plan from the beginning and an important objective has been to create a legacy for the event and to inspire youngsters and I feel we have achieved a lot of that. "We have hosted and staged a lot of kids' activities throughout the tournament over the years and that has helped grow interest."