Coco Gauff broke down in tears during an emotional press conference following her surprise exit from the Australian Open at the last-16 stage on Sunday. The 18-year-old usually cuts a composed figure under the glare of the world's media, despite her tender age. But it all became too much when asked about the frustration she felt during her 7-5, 6-3 fourth-round defeat to Latvia's Jelena Ostapenko, the 2017 French Open champion. "I worked really hard and I felt really good coming into the tournament, and I still feel good," Gauff told reporters. "I still feel like I've improved a lot. But, you know, when you play a player like her and she plays really well, it's like there's nothing you can do." The prodigiously talented American, who must now wait at least a bit longer for a first major crown, added: "I feel like today I would say nothing because every match you play a part in, but I feel like it was rough. "So it's a little bit frustrating on that part,” AFP quoted her as saying. Her voice suddenly began to crack, the tears flowed and the teenager was offered a tissue, before saying: "I'm OK. We can keep going." Gauff gathered herself to say she would now be supporting her doubles partner Jessica Pegula, who was later playing another former French Open champion, Barbora Krejcikova, for a place in the last eight. "I hope that she continues well in the tournament now that I'm out," Gauff smiled. "I hope she wins it." Gauff and Pegula, the women's doubles second seeds, will play for a place in the quarter-finals Monday against Miyu Kato of Japan and Aldila Sutjiadi of Indonesia. "I'm excited to play doubles. I think it gives me a chance to still be around and I definitely enjoy just competing in general," said Gauff. "So I think it will help me (get over defeat), just let me play with some frustration. "I think doubles has taught me how to play, after losing, how to play with frustration, and that's what I felt like today. I was frustrated."