Tennis coach Alexander Waske says a six-week spell at his academy in 2011 helped lay the foundations for Angelique Kerber's Australian Open triumph.
Kerber trained at the facility established by Waske, a former Australian Open and French Open doubles semi-finalist, prior to reaching the US Open semis five years ago.
And Waske, who operates the academy alongside his ex-Davis Cup team-mate Rainer Schuttler, believes they helped to equip their fellow German with the skills needed to defeat Serena Williams, as she claimed a maiden grand slam triumph at Melbourne Park on Saturday.
"I talked with Angelique after Wimbledon in 2011 (where she was beaten in the first round)," Waske told Omnisport.
"She was a bit confused, had little confidence and didn't know where she was going ... she was in bad shape and scared because she was falling down the rankings.
"We talked to her and suggested that she should train six weeks with us. She was against that at first because she thought she would lose too many points and would have to compete in Challenger events. But we told her over and over that she had to get in shape first, in order to win good tournaments. We took a week-by-week approach and she realised that she was not ready yet to compete.
"After five or six weeks, she went to [the Texas Tennis Open in] Dallas, reached - as an unseeded player - the semi-final and the week after that played at the US Open. There, she had to fight in [the] beginning, then had a good win against [Agnieszka] Radwanska and after that she reached the semi-final," he said, referring to Kerber's defeat at the hands of eventual winner Samantha Stosur.
"She worked very hard for that success and in just five weeks she was the number 35 in the world," he added.
"After that, everything looked much better ... she started her preparation for the next season on November 6. I think no other player started that early. She really was motivated because she saw that she had much better chances when she was in better shape. Seven weeks of preparation were very hard, I tip my hat that she pulled it off. And it paid off in 2012, where she finished the year as the number five in the world."
Kerber, 28, has now surpassed her previous highest ranking, moving up to second in the world behind Williams after beating the American in three sets on Rod Laver Arena.