Andy Murray's former coach Leon Smith believes the 25-year-old's victory in the US Open final is the reward for years of dedication to the game.
Smith, Britain's Davis Cup captain and head of men's tennis at the Lawn Tennis Association, knew from an early age Murray had the talent which he has finally realised with a victory over five sets against Novak Djokovic at Flushing Meadows.
Smith, who was Murray's first professional coach, told BBC Radio Five Live: "I'm so pleased for Andy, because knowing him you see how much work he's put in, not just this year but over the years.
"He's really worked so hard, physically and mentally to get his game to this level."
Smith believes Murray's Olympic gold medal win when he defeated Roger Federer in straight sets at Wimbledon gave him a major lift.
"Ever since he won the Olympics he has walked around with a lot more confidence. After winning yesterday it's going to do even more so now.
"For a great summer of British tennis this is the icing on the cake."
Murray's present coach Ivan Lendl said the 7-6 (12/10) 7-5 2-6 3-6 6-2 win over Djokovic had made it a "fantastic year" on the back of his Olympic success.
"I'm very happy for him. It's a great achievement for him and let's hope he can continue and rack up many more," said Lendl.
British doubles player Ross Hutchins described Murray's win as "monumental" and said the moment Murray achieved a second break of serve in the final set meant his fans were able to relax.
"When he got that second break we all felt a bit more comfortable and at ease that he was going to get over that winning line that we've all been waiting for him to get over for so long," said Hutchins.
"It's a great result, for Andy and for Great Britain in this incredible summer.
"On the same day that Fred Perry won it 76 years ago I think it was written in the stars, Lendl winning it on his fifth grand slam final and Andy doing the same it's an incredible achievement."
Former British number one Greg Rusedski, who tasted defeat in the US Open final in 1997, knew how much the victory meant.
"That was unbelievable," he told Sky Sports 1.
"If you look back, Fred Perry won his last major on September 10, and Andy Murray has won it on September 10.
"At the end of the day he found a way to get it done and found a way to control his emotions.
"He can thank Ivan Lendl for that. You have to give him so much credit for what he's done, to keep believing in what he's done.
"It shows you what a champion he is and, having won this, he can go on to win many majors and maybe end the year as the world number one."
Mark Petchey, Murray's former coach who commentated on the game for Sky, added: "I'm more thrilled he's won it like this. It shows he's unique and a bit special. It speaks volumes for Andy.
"It's so special, I had this thought at match point, I was thinking of when I once played horseshoes with him at his house," Petchey recalled of his early days with Murray.
"You knew he had a touch of genius about him and I am incredibly proud. He had so much courage. We need to make the point that he elevated his game and he took it to Novak."
Former Davis Cup captain John Lloyd told BBC Radio Five Live: "What a performance, that was just epic, just a dazzling performance from Murray.
"Mentally to come back from those positions - losing a two sets to love lead - how on earth did he do it?"
David Cameron hailed Murray's win as a "truly great victory" that continued the golden summer of sport.
The Prime Minister took to micro-blogging site Twitter to say: "Delighted Andy Murray is continuing a golden summer of sport by winning the US Open. A truly great victory."
Scottish First Minister Alex Salmond added: "Congratulations to Andy Murray on what was a fantastic performance.
"This is another brilliant win over Novak Djokovic and continues an amazing year for Andy.
"Now Olympic and US Open champion, Andy truly is a Scottish sporting legend and I'm certain that more grand slam titles will follow."
Former British number one Roger Taylor, a four-time grand slam semi-finalist, believes Lendl's contribution should not be overlooked.
The 70-year-old told Sky Sports News: "So much confidence has come from Andy's Olympics win and Lendl has added a great presence.
"Andy respects him and Ivan has realised Andy needs to play closer to the baseline."
It also took Lendl five grand slam finals before he claimed his maiden title - at the 1984 French Open - before going on to win seven more.
"There is such a similarity (between the two)," added Taylor. "It will have given Andy more belief to see Ivan go on to win many grand slams and it took him five (finals).
"He (Lendl) has made a great difference, he is a great character and has gelled the team together."
Taylor continued: "Andy is on top of the world, very few people can beat him and now with the added confidence from the Olympics I am sure he will go on to win many grand slam titles and become number one in the world.
"Finally British tennis is back on the map."
Former British player Andrew Castle, who now commentates on tennis on TV, said Murray had been inspired by the crowd after losing the Wimbledon men's final to Federer to go on to beat the same opponent to claim Olympic gold.
"What helped him to that was the crowd, the spirit we have had this summer," said Castle, paying tribute to the part British fans have played throughout the Olympics and Paralympics.
"I cannot believe that Great Britain got it so right. Now the challenge is to keep it all going," Castle added on BBC Radio Five Live.
Roger Draper, chief executive of the LTA, said: "We are really proud of Andy and what he has achieved. We see the hard work that he puts in day in and day out. It's a fantastic achievement for Andy."
Draper praised Murray for winning Olympic gold against Federer and then silver in the mixed doubles with Laura Robson before claiming the US Open, playing in an era which features Federer, Rafael Nadal and Djokovic.
"To win Olympic gold, to beat the greatest tennis player on Centre Court, to then win the silver with Laura Robson and then again to go out and be the first British man in 76 years to win a grand slam has been a phenomenal achievement," Draper added on BBC Radio Five Live.
"He's done it in an era where you've got not just Roger Federer, the greatest player that's probably ever lived, but you've got Rafa Nadal, Novak Djokovic as well."