Melbourne: Stan Wawrinka believes bringing Magnus Norman on board as coach was the "final piece in the puzzle" that helped transform him from underachiever to grand slam champion.
The Swiss, who crushed American Steve Johnson 6-3, 6-4, 6-4 on Wednesday to reach the third round of the Australian Open, had never been beyond the quarter-finals of a grand slam event before the pair teamed up in April 2013.
Since then, Wawrinka has won three grand slam titles and established himself inside the world's top five.
"He's the one who came to add the last piece of the puzzle, I would say," Wawrinka said in an interview at Melbourne Park, where he is fourth seed.
"He arrived when I was probably ready to be where I am right now, and he showed me the way.
"He's a big part of my success, that's for sure, because since he arrived I am a completely different player (although) my success now is also because of everything I have done for 15 years."
Former world number two Norman had taken Robin Soderling to the top 10 and two French Open finals only for the younger Swede's career to be prematurely ended by glandular fever.
Wawrinka had seen what Norman had done with Soderling and asked him to come on the road with him as early as 2011.
"I think Stan was trying to work with me for a while," Norman told Reuters.
"I think he mentioned that he was a little bit impressed by the work I did with Robin.
"His agent approached me a few times but we were just expecting twin girls so I couldn't really travel in the beginning. But then after a year and a half I said, 'okay, let's try it.'"
Norman, who reached the French Open final in 2000, instilled in Wawrinka a belief that he belonged at the very top of the game.
And Wawrinka blossomed, winning the Australian Open in 2014, the French Open in 2015 and last September, the U.S. Open.
Wawrinka said the pair gelled from the start.
"He knows me really well, he feels me well so he can see in a match how it's going," the 31-year-old said.
"As a coach, he knows what he's doing and what he's doing is amazing because he helped me to reach the results I had since four years I think we're quite on the same page."
In the first round on Monday, Wawrinka flirted with an early exit when he came from a break down in the final set to beat Martin Klizan of Slovakia.
When asked if he always had a good idea how Wawrinka was going to play, Norman just laughed.
"Not really," he said. "No, trying to figure it out and trying to work on the consistency, which is always going to be an issue, I think. But no, it's tough to read but the more matches he plays the better he gets."
Wawrinka added the former Wimbledon champion, Richard Krajicek, to his team during last year's grasscourt season. The Swiss said the fact that Norman was willing to let someone else join the team showed his generosity.
"He does not think he is the best and he is doing what he thinks is the best for the player," he added. "He is open with anything and that's one of his best qualities."