New world number one Angelique Kerber highlighted her improved mental preparation as the reason for a superb breakthrough year that has seen her win two grand slams.
The German defeated Karolina Pliskova 6-3 4-6 6-4 in Saturday's US Open final to add to the Australian Open crown she won in January.
Kerber consequently ended Serena Williams' stunning 186-week reign as the world's top-ranked player, having also reached the Wimbledon final in 2016 - where she lost to Williams.
The 28-year-old had previously been tagged as somewhat of an underachiever, with her best performances at a slam prior to this year coming in semi-final runs to the 2011 US Open and the following year's Wimbledon, and she did not make the second weekend of any major in 2015.
That has all changed now, though, and Kerber believes her success is down to an improved mentality.
"A lot of things happened and changed this year," Kerber, who also made the final of the Rio Olympics, told Omnisport.
"Last year I was sitting at home, making my preparation and my goals were to be playing better in the big tournaments, especially in the majors.
"Right now, to win two grand slams, being the number one in the world, I think the key was more my mental side.
"I was trying to put everything together, be more positive and I had all the confidence from the years before."
Kerber broke through for her maiden major success at Melbourne Park, beating Williams in the final.
Adding another title at Flushing Meadows has given her further belief in her game.
"For me it was really important to show also after my first grand slam in Melbourne that I can still win a few more," Kerber added.
"After that, I reached the final at Wimbledon, so that was one step after.
"And here, to now being a grand-slam champion from the US Open, the second title in one year, that gives me a lot of confidence as well that it's not one grand slam that I won at the beginning of the year."