Andy Murray was among a number of big names to advance at the China Open on Tuesday and revealed he is now finding greater enjoyment in his tennis after shocking Matteo Berrettini.
Former world number one Murray has three grand slam titles to his name but is ranked just 503rd as he continues his return from hip resurfacing surgery, having been set to call time on his career earlier this year.
Meanwhile, Berrettini is the world number 13 and reached the US Open semi-finals less than four weeks ago.
But in his most notable victory of 2019, Murray upset the odds to defeat the eighth seed 7-6 (7-2) 7-6 (9-7) in Beijing and move into the second round.
MORE: Barty, Osaka and Wozniacki power through in Beijing
The Scot took the opportunity afterwards to explain a more positive approach to the sport as he edges closer to full fitness.
"I think just not being in pain now is making tennis a little bit more fun so the practice and the preparation for tournaments is just a lot easier," Murray said, as reported by Eurosport.
"In the last few years, that really wasn't the case and I was finding it all really stressful, I wasn't getting much enjoyment out it. So it's a little bit different now, which is nice."
Over here, Andy! #ChinaOpen | @andy_murray pic.twitter.com/s42DHmDaWA
— ATP Tour (@ATP_Tour) October 1, 2019
Murray faces fellow Brit Cameron Norrie next on Wednesday and added: "Hopefully, I can have a good run here. That was a good start for me. I think I play again tomorrow so that will be a good test for me.
"It's the first time I will have played sort of high-level back-to-back days, so I will see how I pull up after that one. But it's a bit of progress for me again this week, which is good.
"I feel like the progress has been quite consistent and hopefully that keeps going through to the end of the year."
Although Berrettini was shocked, several other contenders came through unscathed on Tuesday, with Dominic Thiem and the previously out of form Stefanos Tsitsipas leading the way.
Top seed Thiem, who could face Murray in the quarters, eased past Richard Gasquet in straight sets, as third seed Tsitsipas was required to recover from a set down and then a break in the third to get the better of Dusan Lajovic.
It was the Greek's first victory since the Citi Open with the exception of the Laver Cup.
Stef in the right direction @StefTsitsipas secures his first win since July outlasting Lajovic 4-6 6-3 6-4 to set a second round date with defending champion Basilashvili.#ChinaOpen pic.twitter.com/66SLnB4xgb
— Tennis TV (@TennisTV) October 1, 2019
Thiem said: "I felt great from the first practice and it's great to get my first win in Beijing. It's one of the strongest tournaments - you can lose every match - but I was very good today."
Fabio Fognini advanced, too, beating Mikhail Kukushkin, but American pair Sam Querrey and John Isner overturned seeds Roberto Bautista Agut and Gael Monfils respectively in a packed draw.
Felix Auger-Aliassime, who plays Alexander Zverev next, Nikoloz Basilashvili and Diego Schwartzman also reached the last 16.