The world number one, who has won the title on each of the eight previous occasions he has reached the semi-finals in Melbourne, claimed his first straight-sets win since the first round, beating the world number 114 6-3 6-4 6-2.
Browsing: Grigor Dimitrov
The Greek fifth seed was solid on serve throughout and played neatly as his Bulgarian opponent lost focus at crucial times under the roof of Court Philippe Chatrier.
The head of the Zadar district crisis headquarters, Sime Vickovic, told state TV HRT that three of the 19 people initially tested were positive.
The 20-time grand slam winner had looked destined for a box-office final against Rafael Nadal in what would have been the great rivals’ first meeting at Flushing Meadows.
Roger Federer destroyed David Goffin 6-2 6-2 6-0 on Sunday to reach the US Open quarter-finals and keep his bid for a record-extending 21st Grand Slam title alive.
Second seed Novak Djokovic reached the quarter-finals of the Paris Masters after Bosnia’s Damir Dzumhur retired with a back injury.
The Bulgarian was pushed to five sets by American Jared Donaldson in the previous round.
Rafa Nadal, who has won the tournament 10 times, also reached the last eight after dispatching compatriot Guillermo Garcia-Lopez 6-1 6-3 and claiming a record-extending 40th consecutive set on clay.
The 31-year-old Nadal needs to win an 11th Monaco title to retain the number one ranking ahead of Roger Federer, and will be a red-hot favourite against Japan’s Nishikori in Sunday’s final
It looked a straightforward afternoon for the 31-year-old Spaniard when he clinched the first three games but Dimitrov worked his way back with a quick break to make it 3-3.
With defending champion Federer and six-times Miami Open winner Novak Djokovic exiting early, the likes of second seed Maric Cilic, Grigor Dimitrov (3) and Indian Wells winner Juan Martin del Potro (5) will all fancy their chances over the coming week.
He is chasing a seventh Australian Open title and started off well with a reassuring 6-1, 6-4 win at the Kooyong Classic on January 10.
Dimitrov, seeded sixth in the tournament, beat 7th seed Goffin 7-5 4-6 6-3 in a thrilling match that lasted two hours thirty minutes
The duo join world number one Rafa Nadal, Swiss ace Roger Federer, Germany’s Alexander Zverev and Austrian Dominic Thiem in the elite eight-man field, after Sam Querrey lost his first round match at the Vienna Open on Tuesday.
The News Agency of Nigeria reports that the seven-time champion now stands alone atop the Open Era list for most Wimbledon quarter-final appearances.
Federer and Nadal are long time friends
The Swiss, returning from a six-month lay-off to rest his left knee, last won a major at Wimbledon in 2012
Japan’s Nishikori prevailed after three and a half hours on a baking Hisense Arena