Plenty has changed for Dominic Thiem in the six years since his previous, and only, visit to the Dubai Duty Free Tennis Championships. Back then, a 21-year-old Thiem was a fast-rising star on the ATP Tour. He was ranked No 47 and had yet to win a title. By the end of that 2015 season, the Austrian was a three-time trophy winner – although none of those came in Dubai, where he was eliminated in the first round. Now Thiem returns to Dubai no longer a young pretender but firmly established among the elite. In the intervening years, he has climbed to world No 4, while a further 14 titles have followed, including the most recent and significant – the 2020 US Open – as well as another three Grand Slam finals. Thiem has for some time been widely regarded as the second-best clay court player in the world – behind only the incomparable Rafael Nadal – but tellingly, most of his recent success has come on hard courts: five of his seven latest titles to be precise, highlighted by that major breakthrough in New York. “It was a lot of work over a long time and little changes and adaptions in my game," Thiem, 27, said of his evolution. "Improving my serve and return was important, approaching the net more, and in general making my whole game style more offensive. It took a long time until it started to work on hard courts but it was worth it.” Indeed it has been worth it. As the Big Three era of Novak Djokovic, Rafael Nadal, and Roger Federer defiantly hangs on against an increasing challenge from the next generation, Thiem delivered the ultimate statement of intent by separating himself from the pack to <a href="https://www.thenationalnews.com/sport/tennis/dominic-thiem-wins-elusive-first-grand-slam-at-us-open-in-pictures-1.1077281">win the US Open last September</a>. To provide some context, 34 Grand Slam tournaments were played between Thiem making his ATP main draw debut in August 2011 and winning his first piece of major silverware – 27 were won by either Djokovic, Nadal, or Federer. Such has been the legendary trio's stranglehold on the four majors, critics have rushed to downplay Thiem's achievement as the Austrian did not face any of them en route to the title. Federer was absent due to injury, Nadal opted to skip his title defence over pandemic-related concerns and to prepare for the rescheduled French Open, and Djokovic was infamously disqualified in the fourth round for striking a line judge with a ball. Thiem, though, scoffs at the idea that his major title needs to have some sort of asterisk next to it. “Nobody knows if I would have won it, but, well, I have the title and that’s all that counts," he said. "Of course, the Big Three is the Big Three but there was also a time before them and nobody asks if Grand Slam titles were worth more or less back then and the same applies now. "A Grand Slam title is always worth the same, so there is really no need to even think about it. After all, my name is on the trophy and it always will be. It doesn’t really matter who I beat and who was or wasn’t there.” Anyway, the US Open is in the past and Thiem is very much focused on the future, starting with his campaign at the Dubai Duty Free Tennis Championships. The tournament top seed received a bye into the second round where he will face either Lloyd Harris or Christopher O'Connell. At this early stage of the season, particularly one as unique and challenging as 2021, now is the chance for Thiem to keep trending in the right direction ahead of his next big aim: the French Open, where he is twice a finalist. "I’m on the right track definitely, but I’m not at the top of my game right now," Thiem said. "Australia [and the 14-day quarantine] was tough to digest in all aspects, so I’m still trying to find my top game and I’m working hard every day. "Strong tournaments like this are always good opportunities to get matches, to play against strong opponents, and I hope I can take another step in the right direction.” As Thiem waits to get under way, a handful of first round matches took place on Sunday. Japan's Kei Nishikori advanced to the second round with a 3-6, 6-3, 6-4 win over American Reilly Opelka. The former world No 4 will next face Belgian fifth seed David Goffin. Australian Open semi-finalist Aslan Karatsev of Russia defeated Bulgaria's Egor Gerasimov 6-4, 6-4 to set up a clash with British 12th seed Dan Evans, while Tunisia's Malek Jaziri notched his 100th tour level win after France's former world No 5 Jo-Wilfried Tsonga retired injured.