Grigor Dimitrov admits he sometimes feels overwhelmed by the sheer number of tactical tools at his disposal, but credits new coach Franco Davin with helping to simplify his improving game.

Dimitrov continued his solid 2016 form on Wednesday to set up a Sydney International quarter-final date with Ukraine’s Alexandr Dolgopolov.

The Bulgarian fourth seed prevailed 7-6 (7-2) 6-4 over Uruguayan Pablo Cuevas at Olympic Park on Wednesday.

It came less than a week after the one-time Wimbledon semi-finalist put up a strong challenge against Roger Federer during his Brisbane International quarter-final.

Dimitrov said he felt good mentally throughout the match despite showing glimpses of exasperation and winning just one of nine break points.

“I was solid throughout the whole match and I created so many opportunities, that I wanted to see some of them … I just wanted to grab a little bit more,” he said.

Confidence is on Dimitrov’s side ahead of next week’s Australian Open.

His performance against Federer aside, the 24-year-old world No.28’s win on Ken Rosewall Arena is his first at this tournament, having been bundled out in the first round of his only other main-draw appearance in 2013.

He put some of his recent success down to his relationship with Davin, Juan Martin Del Potro’s former coach with whom he linked in September.

Dimitrov could not put his finger on how the Argentine’s approach is different from that of previous mentors, including Australian Roger Rasheed, only that it’s working.

“He sees in me (things) that maybe I haven’t seen, nor anyone else,” Dimitrov said.

“We’re still adjusting to certain things, but overall we had a great off-season.

“(We worked on) how to show your true colours a little bit, your identity as a player.

“It sometimes is kind of tough when you have so many tools in your bag and you don’t know which one to pick.

“We’re trying to simplify the game as much as possible.”

Dimitrov has beaten Dolgopolov in three of the pair’s four previous meetings, but still saw Thursday’s clash as “tricky”.

“He’s a dangerous player, you never know what to expect,” he said of the world No.36 who ousted American qualifier Alexander Sarkissian 7-6 (8-6) 6-2 on Wednesday.

“Especially here, the conditions are pretty suitable for him – it’s a faster court and a little bit windy.”

Defending Sydney champion Viktor Troicki is also safely through to the quarter-finals after a comfortable 6-1 6-4 win over Tommy Robredo.

The Serbian third seed will face Nicolas Mahut on Thursday after the Frenchman upset Italian fifth seed Andreas Seppi 6-3 1-6 6-3.

Earlier, local wildcard James Duckworth lost his second-round match 7-6 (7-5) 6-4 to French sixth seed Jeremy Chardy.

Chardy will take on Luxembourg’s Gilles Muller in the last eight, after Muller’s second-round opponent, second-seeded Austrian Dominic Thiem, retired with a foot blister while trailing 7-6 (7-2) 2-2.