BRISBANE, Australia - An opening day of upsets at the Brisbane International continued with the unseeded Danielle Collins ousting No.4 seed Elina Svitolina in stunning fashion, 6-1, 6-1 in just 56 minutes.

The American blitzed a series of scorching winners past Svitolina en route to claiming her third career Top 10 win - and first since being diagnosed with rheumatoid arthritis last October. It is a welcome return to form for Collins, who reached her maiden Grand Slam semifinal at the Australian Open last January but, following her diagnosis, ended 2019 dropping down beneath WTA level - only to lose to World No.181 Anhelina Kalinina in the second round of the Houston 125K and to World No.316 Gabriela Talaba in the Naples ITF W25 quarterfinals.

These troubles were firmly in the past, Collins emphasized afterwards. "It's been put behind me," she said. "I had been feeling symptoms for quite some time and it just took a while for them to make the right diagnosis. I've been able to receive medical treatment for it that allows me to do what I'm able to do - it's helping me feel better more consistently, and this is the best I've felt in probably over a year."

This was underlined by Collins's phenomenal display of raw power today. The 26-year-old managed to grind out a nine-minute opening service hold, saving four break points along the way - but that mini-marathon was no foreshadowing of the rest of the match. Indeed, the opening game alone would be almost one-third the length of the entire rest of the set: from 1-1, Collins steamrollered Svitolina with a relentless barrage of first-strike attacks, conceding only six more points in the opening act. There was no let-up in the second set, either: from 0-1 down, Collins dropped only eight further points as she raced through six straight games for a "hidden bagel".

"It's really fun," she laughed when asked how the match had felt. "Every day I wake up and I put so much effort into what I'm doing on the practice court - I'm so detail-oriented, I'm hitting so many balls for so many hours on court, and off court I'm doing as much as I can do from a fitness and strength standpoint, from conditioning to recovery to going to the chiropractor to going to the doctor to working on my mental side. So it's really rewarding to me to go out there and get a win against a top player in under an hour."

The World No.27's returning in particular was breathtaking: Collins scored six clean winners off the return over the course of the match - and though she made sure to punish Svitolina's subpar 57% first serve percentage, Collins did not confine herself to merely attacking the Ukrainian's softer second delivery. By the second set, Svitolina would see even her first serve dismissed on a regular basis.

But Collins truthfully excelled in every aspect of the game. Striking five aces of her own, she would not face a break point again after that opening tussle; off the ground, she was able to hammer winner after winner off both wings, usually managing to create the space for her shotmaking within the first few strokes of the rally.

Svitolina would have no answer for Collins' game: attempting to impose herself only led to an uncharacteristic number of errors from her own racquet, while a sprinkling of three double faults did not help either. Towards the end, the WTA Finals runner-up and 2018 champion here was virtually a spectator, watching as Collins whipped winner after winner past her - finishing, appropriately, with a final one off a forehand return.

Afterwards, Collins discussed "the biggest thing" in helping her be at her best: expanding her team to include a full-time fitness coach, Tom Couch, and a full-time physiotherapist, Evie Maguire, as well as coach Jay Gooding and hitting partner Baker Newman. Having grown up unable to play as many tournaments as some of her peers, Collins is more aware than most of the importance of this financial commitment now that she can afford it.

"I really want to be No.1 in the world one day and win a Grand Slam at some point in my career," she asserted. "So I've invested in myself by having a full team and making sure I have all the resources I can have. I'm really backing myself financially to have my career on my terms, to have four people on the road helping me constantly. That's a big positive - last year there was so much inconsistency with coaching changes and letdowns where I thought someone was going to work with me consistently and then they dropped me. Now I feel I'm on a good stretch... with people who are a positive influence, not just from a tennis perspective but personally as well."

In the next round, Collins will bid to reach her first quarterfinal since Charleston last year against either Donna Vekic or qualifier Yulia Putintseva.

2020 Brisbane highlights: Collins sweeps past Svitolina