Melbourne, Jan 19 (IANS): Bulgaria's Grigor Dimitrov on Friday booked a place in Australian Open round of 16 for the fourth time, earning another ugly win over Russian Andrey Rublev 6-4, 4-6, 6-4, 6-4.

After getting through a five-set match in the previous round against American qualifier Mackenzie McDonald, the third seed managed to win despite not giving his best, reports Efe.

"These are the most important matches for me when things are not working and I'm able to find a way," Dimitrov said after the win. "I knew what to expect. I knew what I had to do, but certain things in my game are not working at the moment. I'm just pleased to win the match."

Dimitrov, the reigning ATP finals champion, committed 61 unforced errors, but he earned his first win over Rublev in the second career matches.

The 26-year-old Dimitrov is scheduled to play either local favorite Nick Kyrgios or Frenchman Jo-Wilfried Tsonga.

Spaniard Pablo Carreño Busta, the 10th seed, defeated Gilles Muller of Luxembourg 7-6 (7-4), 4-6, 7-5, 7-5.