Novak slayer Istomin backs up Open win

Giantkiller Denis Istomin has backed up his shock win over Novak Djokovic to advance to the fourth round of the Australian Open.

The 30-year-old Uzbek defeated 30th seed Pablo Carreno Busta on Saturday 6-4 4-6 6-4 4-6 6-2 in just under three-and-a-half hours.

Istomin will face Grigor Dimitrov or Richard Gasquet in the round of 16, equalling his best performance in a grand slam.

The world No.117's stunning five-set win over second seed and six-time Open champion Djokovic on Thursday blew the men's draw wide open, and Istomin said he had been motivated to back it up.

"It's mentally tough because ,after beating Novak, I mean, Carreno is also a great player," he said.

"After beating Novak, I don't want to lose like three sets in a row, and then everybody saying that I was dead."

Beyond some minor muscle tightness, Istomin said he had not suffered any ill-effects after enduring back-to-back five-set marathons.

But he has had to adjust to his new-found fame after being inundated with phone calls and Facebook messages after his win over Djokovic.

"I have no time to answer everyone, so I just put the 'like'," he said.

"Sorry, but it takes one month to answer to everyone. I need to prepare for the next match, and everybody was happy."