Vinci's big serve and big forehand - and her lethal backhand slice - were hitting their targets throughout the match against the No.7-seeded Stosur, as she raced through the first set and fought back from 2-0 down in the second set to reach the semifinals in straights in an hour and 18 minutes, 62 64.
"It was a great match for me, a great performance," Vinci said. "She has a great serve, a great kick serve, and for me it was difficult to return because I have a one-handed backhand. But today I played aggressively on the court when I could and it was a good game for me, just like it was yesterday."
There was one shot Vinci stayed away from. "She has an unbelievable forehand," Vinci said. "I had to play a lot to her backhand, and I tried to change from slice to topspin when I had the time."
Vinci is now through to the biggest WTA semifinal of her career, and her second at the Premier level (Dubai has more than three times the prize money of the other Premier tournament she reached the semifinals of - Eastbourne in 2005). This is also the first time Vinci has beaten two Top 10 players at the same tournament, having defeated Angelique Kerber in the third round on Wednesday.
It doesn't get any easier, though, and not just in an on-paper sense - next up for Vinci is her best friend on the tour, No.5 seed Sara Errani, who rebounded from a second set lapse to beat Nadia Petrova in three sets, 64 06 63. Petrova actually won more points than Errani in the match, 105 to 104.
"The first two games of the second set were so long, the second set was very long even if it was 6-0," Errani said afterwards. "In the third set I just tried to get more aggressive and more concentrated. I tried to show her I wasn't tired. I just tried to recover and be positive and face these things."
Errani and Vinci aren't just best friends on the tour, they are also the No.1 doubles team in the world together - their respect for each other was never more evident after they played each other in the US Open quarterfinals last year, with Errani winning but her totally silent celebration saying it all.
"Normally she's with me on my side of the net and not on the other one, so to see her on the other side is tough because one of us will lose," Errani commented. "She's an amazing person outside the court. Outside the court she will always try to help you when she can. She's like a sister to me. We stay together maybe 300 days a year. Of course we have had a lot of good moments together.
"I will have to think about it as just another tennis match, and not that it's against her. I just have to go on the court and do my best. The good thing is one of us will be in the finals here."
Vinci echoed Errani's sentiment. "It will be different mentally because I know her, she's like a sister for me and we play doubles together all the time," the Italian explained. "It will be tough."
While one semifinal will be a battle between best friends, the other will feature two players trying to recapture the form that saw them finish 2011 as the Top 2 players in the world - Petra Kvitova and Caroline Wozniacki. The No.8-seeded Wozniacki was the first to move through, battling more than two and a half hours and defending against some huge hitting from Marion Bartoli to win, 46 61 64.
"It was disappointing to lose that first set after I had been up; I'm happy I turned it around," Wozniacki said. "In the third set I was down 2-0 and it could have been 3-0, and all of a sudden it wasn't looking good, but I kept fighting and every game was close, and I'm happy I ended up winning it."
Wozniacki was particularly troubled by one shot. ""Usually girls have a first serve and a second serve, but Marion doesn't have a second serve, she has two first serves. Both serves are at least 150 or 160Ks. So you just need to be on your toes. She steps in, she's in the court on your serves, as well - you feel the pressure. But you just need to be ready and know it's going to be coming fast at you."
The No.6-seeded Kvitova pulled off a 62 64 upset over No.3 seed Agnieszka Radwanska at night, taking complete control of the match from the beginning - she finished with 37 winners to 38 unforced errors, while Radwanska finished with a much more conservative 6 winners and 5 unforced.
Kvitova recorded her first win over a Top 5 player since the 2011 season, when she finished the year at No.2 in the world (and Wozniacki, of course, finished that year ranked No.1 in the world).
Errani leads Vinci in their head-to-head, 4-2, while Kvitova and Wozniacki are tied in theirs, 3-3.