New York: Grigor Dimitrov was once in danger of spending his career either struggling to live up to being dubbed the "new Federer" or being known as the boyfriend of Maria Sharapova.
But with Federer sidelined from the US Open and with Dimitrov and Sharapova no longer the sport's golden couple, the 25-year-old Bulgarian is enjoying having the spotlight lifted from him.
"I think a lot has changed over the past year and a half for me. I fell in love with tennis again. It's simple as that," said Dimitrov, a former world number eight, now down at 24 in the rankings.
A 6-4, 6-1, 3-6, 6-2 win over Portugal's Joao Sousa on Saturday gave him a place in the second week of a Slam for the first time this year.
World number two Andy Murray awaits him on Monday with a spot in the quarter-finals at stake.
Dimitrov appeared to have the world at his feet in 2014.
Sharapova was his girlfriend and he reached the semi-finals of Wimbledon and quarter-finals of the Australian Open.
But his form went downhill in 2015 and in the first half of this year.
Between May and June, he endured a six-match losing streak and his ranking slumped to 40, his lowest in three years.
The summer has seen a resurgence with Danny Vallverdu -- once part of Murray's coaching team -- in his corner becoming the Bulgarian's sixth coach since 2009.
At the Toronto Masters, he reached the last-eight, losing to Kei Nishikori.
In Cincinnati, on the eve of the US Open, Dimitrov made the semi-finals at a Masters for the first time, defeating world number three Stan Wawrinka in the third round before losing to eventual champion Marin Cilic in three sets.
"I have started to enjoy the process again. I'm enjoying the work again. I'm enjoying waking up in the morning early to come to practice. I'm enjoying doing the ice baths again. I'm enjoying pretty much everything that I do," he said.
"You don't think of anything else. I started to enjoy those butterflies before a match, complaining to your coach that you're, like, short of breath because you're so nervous to come on court.
"Those are moments I'm sure I'm always going to appreciate hopefully for the rest of my career."
Against Wimbledon and Olympic champion Murray, he has a 6-3 losing record, but he came out on top in their last clash in Miami in March.
"I think our styles just kind of fit our games. There's going to be a lot of challenges against Andy," he said.
"He's going to be ready as ever. He's just really confident right now. He's been playing extremely good tennis. He knows what to do."