Dominic Thiem became the newest Grand Slam champion with his recent US Open win. A sport that has been largely dominated by Roger Federer, Rafael Nadal and Novak Djokovic over the last decade, has now found a player who can challenge the hegemony of the Big 3.While the Austrian’s rise may not be good news for Novak Djokovic and Rafael Nadal, some believe it presents Roger Federer with some positivity - that his record of 20 Grand Slam titles can last a little bit longer.Former Swiss Olympic gold medalist Marc Rosset agrees with that view. Writing in his rather controversial blog, the Swiss lauded Dominic Thiem's achievement and asserted that the Austrian’s arrival was great news for Roger Federer.🎾🇨🇭"Immense sketch". "Complètement perdus dans leur tête". "Mental de majorette". "Trouillomètre à zéro"...➡️https://t.co/VeugNC3IsVL'un des blogs les plus drôles et pro-@rogerfederer de la Toile revient sur la peur de vaincre 🇦🇹🇩🇪 post-Big 3 de la finale du dernier @usopen pic.twitter.com/oi3LxsGvMg— Anthony DIAO (@anthony_diao) September 23, 2020Dominic Thiem has shown terrific improvement in his skills and mentality of late, as evidenced by his four Grand Slam final appearances. And with his win at the US Open, Thiem has established himself as an able challenger to the Big 3. Dominic ThiemRosset believes that Thiem was the most deserving candidate to win the US Open given his form throughout the tournament.“In short, we will only remember the name of the winner and it is, therefore, Dominic Thiem,” Rosset wrote. “Bravo to him anyway. He deserves this title and he flew over the tournament before his initial crack in the final."Rosset further believes that Dominic Thiem can emulate Andy Murray by challenging Novak Djokovic on hardcourt and Rafael Nadal on clay. “The one who can become the Andy Murray of the 2020s finally defeats the Indian sign (curse/bad luck) and we are counting on him to continue his momentum and confirm that he is indeed a great champion by going on to defeat Nadal and Djokovic on their surfaces,” Rosset added.Dominic Thiem is Roger Federer's best ally today: Marc RossetRoger FedererWinning Grand Slams against this duo would benefit not only Dominic Thiem but also Roger Federer.On one hand, the Austrian would increase his own Grand Slam tally. And on the other, he would also prevent Novak Djokovic and Rafael Nadal from closing in on Roger Federer's tally.Federer has always led both Rafael Nadal and Novak Djokovic in the Grand Slam leaderboard, but now that lead is massively threatened.In the past, whenever the two threatened to equal him, either the Swiss responded with another Slam win or a different player came along to stop Nadal and Djokovic. Needless to say, Dominic Thiem is tipped to be that player in this decade - much like Murray and Wawrinka were in the previous one. Roger Federer and Dominic ThiemRosset thus believes that Thiem is Roger Federer’s best bet to protect some of his records in tennis.“Let's be honest: the Austrian is Roger Federer's best ally today,” Rosset continued. “If the Master hopes to keep some of his records, he will have to count on Thiem in the next few years.