Jan. 22 (UPI) -- Rafael Nadal continued to roll with a straight-sets victory over Frances Tiafoe and Danielle Collins continued her storybook run with a come-from-behind win over Anastasia Pavlyuchenkova at the Australian Open on Tuesday.
Nadal had to battle a bit before earning a 6-3, 6-4, 6-2 victory.
"It's so good to be back where I am," Nadal told reporters.
Nadal and Tsitsipas will meet in the semifinals Wednesday.
On the women's side, Collins defeated Anastasia Pavlyuchenkova 2-6, 7-5, 6-1.
Collins had never won a main draw match in a Grand Slam event before this Australian Open, of which she has reached the semifinals.
"I think not being a superstar at a young age certainly humbled me, made me work harder for things," Collins said after her quarterfinals win, via ESPN. "I was talented and athletic, but maybe not to the level that other players were at, like, 14, 15, 16. Not being a child prodigy, I went a different route. I wasn't really sure if I could make it playing professional tennis when I was that age. Going to college was really crucial for me and my development. I think it's made me hungrier."
Her opponent there will be eighth-ranked Petra Kvitova, who advanced with a 6-1, 6-4 win over Ashleigh Barty.