Some of the so-called true blue courts at the Australian Open were coated in red after a rain front that lashed Melbourne overnight pushed through a dust storm from the northwest and left its mark on the city and the tournament.

Crazy weather has plagued the season-opening major at Melbourne Park and caused yet more disruptions on Day 4, when two-time major winner Garbine Muguruza had to wait for the roof to be closed on Rod Laver Arena before completing her 6-3, 3-6, 6-3 second-round win over Ajla Tomljanovic.

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Ground staff wash red dust tainted water from an outside court as rain delayed play at the Australian Open tennis championship in Melbourne, Australia, Thursday, Jan. 23, 2020. (AP PhotoAndy Wong)

Some of the so-called true blue courts at the Australian Open were coated in red after a rain front that lashed Melbourne overnight pushed through a dust storm from the northwest and left its mark on the city and the tournament.

Switzerland's Belinda Bencic celebrates after defeating Latvia's Jelena Ostapenko during their second round singles match at the Australian Open tennis championship in Melbourne, Australia, Thursday, Jan. 23, 2020. (AP PhotoAndy Brownbill)

Smoke from devastating bushfires on Australia's east coast caused air quality in Melbourne last week to be ranked among the worst in the world, and impacted qualifying for the season's first tennis major. Heavy rain on three of the first four days of the tournament has caused more difficulties for players and organizers. On Day 3, a blustery wind made conditions difficult.

Switzerland's Belinda Bencic celebrates after defeating Latvia's Jelena Ostapenko during their second round singles match at the Australian Open tennis championship in Melbourne, Australia, Thursday, Jan. 23, 2020. (AP PhotoAndy Brownbill)

U.S. Open semifinalist Bencic beat 2017 French Open champion Jelena Ostapenko 7-5, 7-5, and 19th-seeded Vekic had a 6-4, 6-2 win over Alize Cornet.

Ball kids dry off outside courts as play is delayed by rain at the Australian Open tennis championship in Melbourne, Australia, Thursday, Jan. 23, 2020. (AP PhotoAndy Wong)

Melbourne Park staff used high-pressure hoses to clean court surfaces. Light rain became heavy in the early afternoon, forcing the suspension of the only two matches that had started on outside courts.

Spectators queue for a show court at the Australian Open tennis championship in Melbourne, Australia, Thursday, Jan. 23, 2020. (AP PhotoAndy Wong)

In showcourt matches scheduled later Thursday, top-ranked Rafael Nadal was playing Federico Delbonis and Nick Kyrgios was set to play Gilles Simon.

Muguruzu said as well as having a “tough battle to the end,” against her Australian opponent, she had to concentrate on staying patient with all the changing weather conditions.

Ground staff wash red dust tainted water from an outside court as rain delayed play at the Australian Open tennis championship in Melbourne, Australia, Thursday, Jan. 23, 2020. (AP PhotoAndy Wong)

Ground staff wash red dust tainted water from an outside court as rain delayed play at the Australian Open tennis championship in Melbourne, Australia, Thursday, Jan. 23, 2020. (AP PhotoAndy Wong)

Smoke from devastating bushfires on Australia's east coast caused air quality in Melbourne last week to be ranked among the worst in the world, and impacted qualifying for the season's first tennis major. Heavy rain on three of the first four days of the tournament has caused more difficulties for players and organizers. On Day 3, a blustery wind made conditions difficult.

On the plus side, there are three stadiums with retractable roofs, so the show court matches will proceed.

In the other completed singles matches Thursday, sixth-seeded Belinda Bencic and Donna Vekic advanced to the third round.

Switzerland's Belinda Bencic celebrates after defeating Latvia's Jelena Ostapenko during their second round singles match at the Australian Open tennis championship in Melbourne, Australia, Thursday, Jan. 23, 2020. (AP PhotoAndy Brownbill)

Switzerland's Belinda Bencic celebrates after defeating Latvia's Jelena Ostapenko during their second round singles match at the Australian Open tennis championship in Melbourne, Australia, Thursday, Jan. 23, 2020. (AP PhotoAndy Brownbill)

U.S. Open semifinalist Bencic beat 2017 French Open champion Jelena Ostapenko 7-5, 7-5, and 19th-seeded Vekic had a 6-4, 6-2 win over Alize Cornet.

“First it was sunny, almost raining, windy," Bencic said. “You just have to accept it and try your best to adapt.”

Heavy morning showers delayed play on all outside courts. That combined with the dust left a layer of red on some outside courts, making them unplayable in the morning.

Switzerland's Belinda Bencic celebrates after defeating Latvia's Jelena Ostapenko during their second round singles match at the Australian Open tennis championship in Melbourne, Australia, Thursday, Jan. 23, 2020. (AP PhotoAndy Brownbill)

Switzerland's Belinda Bencic celebrates after defeating Latvia's Jelena Ostapenko during their second round singles match at the Australian Open tennis championship in Melbourne, Australia, Thursday, Jan. 23, 2020. (AP PhotoAndy Brownbill)

Melbourne Park staff used high-pressure hoses to clean court surfaces. Light rain became heavy in the early afternoon, forcing the suspension of the only two matches that had started on outside courts.

The Australian Broadcasting Corp said the “dirty rain” from the overnight downpour had forced public pools to close and left some cars with the appearance of having been "sprayed with mud".

Bureau of Meteorology senior meteorologist Richard Carlyon told the ABC the brown rain was the result of dust storms, not bushfire smoke.

Ball kids dry off outside courts as play is delayed by rain at the Australian Open tennis championship in Melbourne, Australia, Thursday, Jan. 23, 2020. (AP PhotoAndy Wong)

Ball kids dry off outside courts as play is delayed by rain at the Australian Open tennis championship in Melbourne, Australia, Thursday, Jan. 23, 2020. (AP PhotoAndy Wong)

In showcourt matches scheduled later Thursday, top-ranked Rafael Nadal was playing Federico Delbonis and Nick Kyrgios was set to play Gilles Simon.

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Spectators queue for a show court at the Australian Open tennis championship in Melbourne, Australia, Thursday, Jan. 23, 2020. (AP PhotoAndy Wong)

Spectators queue for a show court at the Australian Open tennis championship in Melbourne, Australia, Thursday, Jan. 23, 2020. (AP PhotoAndy Wong)