MELBOURNE, Australia - Timea Babos backed up her doubles triumph at the BNP Paribas WTA Finals Singapore presented by SC Global to stun No.10 seed CoCo Vandeweghe in singles, 7-6(4), 6-2 in the first round of the Australian Open.

"It's an amazing feeling to be here," a breathless Babos said during her on-court interview. "The last couple times I played at Grand Slams, I played Top 10 players or Maria Sharapova, pushing them all to three sets. Today I could manage the win and it was amazing.

"I think in the past, I didn't always take the opportunities at the right time," Babos continued in post-match press. "Today, I really went for it in all the key moments. I was aggressive and made the right decisions, and so I think that was important."

Babos ended a tough 2017 season by winning the biggest title of her career alongside Andrea Hlavackova in Singapore, and took that momentum into 2018, reaching the quarterfinals of the Shenzhen Open and bringing it in full force against Vandeweghe on Monday.

"I usually don't start the season well; I need some time. But I played well from the first tournament I played, so I came here with a lot of belief. I also changed racquets over the off-season, which I think helps me be more solid. I had very good preparation.

"I'm definitely better physically, but the bigger change is mental. I'm just focusing on myself and what I want to do. I know that I'll fight for every point, which is a big advantage. There won't be a moment where I give up, even when I was down a break and she was winning. I was able to stay in it and it really paid off."

A semifinalist at last year's Australian Open, Vandeweghe strode to a confident lead to start the first set, but struggled to match the Hungarian's pace from 4-2 up and found herself down 5-1 in the second.

"This is the first time I've been out of bed in four days," a hoarse Vandeweghe revealed in her post-match press conference. "I've had the flu since Sunday. The doctor gave me some medication, but it's not working all that well, so here I am.

"I did the best I could with what I had today. I thought she played really well. I try to be as healthy as I can throughout the year. All things considered, I played pretty well for not hitting a ball in four days and feeling like I do. Luckily for me, there's three other Grand Slams."

The American fought through her frustration to force Babos to serve for the match, but the unseeded 24-year-old gamely held to love to clinch victory after over two hours on Hisense Arena.

"I tried not to buy into the things going on around me, and you have to be prepared for anything against the kind of opponent who will break racquets, but then hit four aces in a row. Even after the point penalty, she hit an ace, so you have to be ready for this to happen.

"At the beginning of the second set, we played some unreal points. It was like a show. I was happy to win them, but it was nothing against her. I can be crazy on court, but not in a negative way! I'm just like this."

Standing between her and a career-best finish Down Under is either former World No.6 Carla Suárez Navarro or qualifier Magdalena Frech.