NEW YORK—Grigor Dimitrov is winning again and, into the second week of a major for the first time this season, he says he’s enjoying the game again, too.

Having gone 2-7 between Istanbul and Wimbledon, the 25-year-old is 10-5 during the hard-court season.

"I'm enjoying playing tennis right now," Dimitrov said. "Obviously I've been striking the ball well, having good results."

The former world No. 8 next plays Andy Murray in the fourth round, and he pointed to renewed enthusiasm as the reason for his recent success.

"I think winning matches always gives you confidence," the Bulgarian said “…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.''

Dimitrov has been coached by Dani Vallverdu since the beginning of the hard-court season, and he says "simplicity" has been at the center of their approach. Vallverdu was previously Murray's hitting partner, and he coached Tomas Berdych.

"On the court we kind of think similar," Dimitrov said. "Now it's more the strategic way, how you're going to prepare for big matches, big tournaments."

It also affects his play on court.

"Especially in those moments—30-30, deuce, break point, anything like that—it's super important to, in a way, go back to the basics, go back to what you've been practicing, to the simple shots,” he said. “For example, play with your big weapons, whether it's your first serve or your forehand.”

Dimitrov is No. 24 in the rankings.