Andy Murray believes his maiden Grand Slam triumph has given him an extra edge when he comes up against the world's best players.
Murray finally lifted the first Grand Slam title of his career in September when he defeated Novak Djokovic in five sets in the US Open final after losing his previous four major finals.
The 25-year-old Scot's triumph in New York not only underlined his right to be rated as equal to his top four rivals Djokovic, Roger Federer and Rafael Nadal.
Just as importantly it has also given world number three Murray, who in the past was often accused of being too passive in big matches, a new-found belief that he can beat the best on his terms.
Murray showed his steely side again on Monday when he kicked off his bid for a first ATP Tour Finals crown by coming from a set down to beat Czech fifth seed Tomas Berdych 3-6, 6-3, 6-4.
"I hope when I'm playing the best players in the world, I'll believe in my shots a bit more and make sure to be aggressive when I can," Murray said.
"I thought I did a good job of that against Tomas. I tried to move forward and take his time away a little bit, which sometimes when I played him in the past, I'd let him dictate a lot of the points.
"Having won a few of the big events this year, and having lost a tough one in Australia against Novak, and at Wimbledon against Roger, I've learnt a lot this year how I need to play those big points in big games."
Murray was also relieved to see off Berdych in the opening group match of the season-ending tournament because he has struggled to close out matches since winning the US Open.
He held match points against Milos Raonic in Tokyo, Djokovic in Shanghai and Jerzy Janowicz in Paris, only to lose on all three occasions, but this time he defeated Berdych on just his second match point.
"I was thinking about the reasons why that had happened," Murray said when asked if those previous failures worried him in the closing stages of the Berdych match.
"The match against Djokovic in Shanghai, I didn't really feel like I did loads wrong in that match.
"The one last week in Paris, I said I was disappointed with. I rushed, didn't concentrate and focus as hard as I needed to. That was why I got broken.
"So today I focused on every point. I got myself pumped up I took my time and served it out well."
This was Murray's first match in front of a British audience since his Grand Slam victory and the Olympic gold medallist admitted the vocal support of the crowd was a major lift at the end of a draining campaign.
"The noise and the atmosphere at the beginning of the match was great," Murray said.
"The last week of the year when everyone's a little bit tired, it does help to have that atmosphere and a big crowd to give you that extra push you need to play good tennis. So, yeah, it was good to be back playing in the UK."