PIX: Djokovic-Kyrgios lose in doubles

Grigor Dimitrov stayed on course for his title defence but women's second seed Emma Navarro was stunned by local favourite Kimberly Birrell at the Brisbane International on Wednesday.

Two-time men's champion Dimitrov downed Aleksandar Vukic 6-2, 7-6(5) to advance to the quarter-finals, overcoming late resistance from the Australian wildcard.

"It's such a home atmosphere, honestly. It doesn’t feel like a tournament to me," the Bulgarian said.

"That's why I think the excitement is different. My attitude I think also changes quite a bit. It's a very special week."

Birrell gave the local fans something to cheer about as she pulled off the biggest win of her career, beating Navarro 7-5, 7-5.

Egged on by the vociferous crowd at Pat Rafter Arena, the 113th-ranked wildcard broke to serve for it at 5-4 in both sets before closing it out on her second attempt.

"I've spent so many hours on this court since I was little," the 26-year-old said.

"I watched the Brisbane International when I was a kid and to get to play here and have the tournament that's basically at home is so special."

The journey of Novak Djokovic and Nick Kyrgios as a doubles pair ended with a 6-2, 3-6, 10-8 defeat by top seeds Nikola Mektic and Michael Venus, who advanced to the quarter-finals.

Kyrgios, playing his first tournament since a wrist surgery in September 2023, was beaten by Frenchman Giovanni Mpetshi Perricard in a battle of big servers in men's singles on Tuesday.

The Djokovic-Kyrgios duo came within two points of a win but an untimely double fault in the match tie-break allowed Mektic and Venus to clinch the nailbiter.

"Down three points in the match tie-break it wasn't looking great, but somehow we got back in there and Mekta hit a great return on match point," Venus said.

Daria Kasatkina overcame Peyton Stearns 7-6 4-6 7-5 in a slugfest lasting nearly three-and-half hours.