ROME -- No.15 Danielle Collins stormed into the semifinals of the Internazionali BNL d'Italia on Wednesday after defeating former No.1 Victoria Azarenka 6-4, 6-3 in the quarterfinals.

Collins joins No.3 Coco Gauff to put two Americans into the Rome semifinals for the first time since Rome hosted an all-American final between Serena Williams and Madison Keys in 2016. Gauff will face World No.1 Iga Swiatek in the other semifinal on Thursday. 

Collins, 30, announced in January that this would be her final season on the Hologic WTA Tour before retiring. The Florida native has now won 19 of her last 20 matches, dating back to the start of the Miami Open, where she captured her first WTA 1000 title. She extended that win streak through a title run on the green clay at the Credit One Charleston Open and ran off 15 consecutive matches before losing to World No.2 Aryna Sabalenka in three sets in the fourth round of the Madrid Open. 

"I'm going out with a bang," Collins said. "I want to go out playing my best tennis because I certainly wouldn't want to go out playing my worst tennis. That does happen sometimes, unfortunately. It's important for me to feel like I got everything I could out of myself as an athlete."

Collins will get her chance to get one back on Sabalenka, as the two will square off in the Rome semifinals on Thursday. Collins has not lost a set in Rome, posting wins over Anna Blinkova, Caroline Garcia, Irina-Camelia Begu and now Azarenka.

"It's super rewarding because you go through periods where you might take three steps forward and four steps back some weeks," Collins said. "It's kind of like the stock market. It's really up and down sometimes.

"So it's been nice to have a stretch when I've just been climbing, because it's not always like that. You have to be really happy for yourself in these moments because it doesn't always work out that way."

How the match was won: Collins struck 14 winners in the first set while holding Azarenka to seven. Azarenka struck first, breaking Collins for a 2-0 lead in the opening set. But the former No.1 played a poor service game to hand the advantage back, striking three consecutive double faults to help the American get back on the board. 

From there, Collins was off to the races. She controlled the center of the court and overpowered Azarenka with her flat, aggressive shots, pulling Azarenka from corner to corner. After building a 5-2 lead, Collins failed to serve out the set in her first opportunity but responded by breaking Azarenka for the set. 

Collins continued her march to lead 4-1 in the second set, but after failing to convert two break points for a 5-1 lead, she played her poorest game of the match to allow Azarenka to close the gap to 4-3. 

Collins responded with the grit and fire that has propelled her to an incredible resurgence. She stepped to the line and struck three consecutive winners to earn triple break point and went on to break and serve out the win after 1 hour and 44 minutes.

Collins finished with 27 winners to 24 unforced errors, while holding Azarenka to 10 winners and 20 unforced errors.