Giant-killing Su-wei Hsieh has paid an emotional tribute to her Australian mentor Paul McNamee after dumping Wimbledon champion Garbine Muguruza from the Melbourne Park draw.
Taiwan's world No.88 eliminated third-seeded Muguruza 7-6 (7-1) 6-4 on Thursday to leave former Open winners Maria Sharapova and Angelique Kerber and French Open titleholder Jelena Ostapenko as the only grand slam champions left in the women's singles.
Hseih was almost in tears as she credited McNamee - the former long-time Australian Open tournament director - who was a conspicuous presence in her courtside box on Rod Laver Arena.
"He's always been around me and supporting me. He's amazing," said the 32-year-old ex-Wimbledon and French Open doubles champion.
"He was helping me to become world No.1 and be successful in doubles.
"But my goal to hire him at the beginning is to win a grand slam and then he pushed me to win two WTA singles (titles) and highest singles ranking.
"So it was amazing. We (have been) working almost four years together. Thank you, Paul."
Hsieh will next play Polish 26th seed Agnieszka Radwanska in the third round on Saturday.
Muguruza had been one of five women with an opportunity to supplant Simona Halep from the world No.1 ranking with title glory at Melbourne Park.