Rising star Daria Gavrilova has caused a major upset at the Cincinnati Masters, beating tournament No.16 seed Sara Errani in the opening round on Tuesday.
The Russian-born Gavrilova, who now lives in Melbourne, beat the Italian 6-1 4-6 6-2.
Ranked No.36 in the world, the 21-year-old sent down five aces in an impressive performance.
Cassey Dellacqua, however, is out of the tournament but not before putting up a brave fight against Mona Barthel.
The world No.60 was beaten 2-6 6-3 7-6 (7-4) in just over two hours by the German qualifier, who is ranked two spots below her.
But all the talk centred around Swiss teenager Belinda Bencic, who maintained her recent giant-killing form with a battling 7-5 6-3 win over higher-ranked German opponent Angelique Kerber.
Bencic, 18, is brimming with confidence after winning in Toronto at the weekend after a tournament which included a stunning semi-final defeat of Grand Slam-chasing world number one Serena Williams.
The teenager, coached by Melanie Molitor, mother of Martina Hingis, said on Tuesday she was pleased with her mental strength after recovering from 5-1 down in the first set to defeat 11th seed Kerber.
“I’m so happy that I could win,” she said of her Toronto title. “It was very nice from the crowd, the great atmosphere on the court. I just tried to fight for every point.
“It’s amazing that I could beat so many players so high ranking and top players in the same week.
“I think I definitely improved my tennis, and I hope I can bring it also to here.”
Bencic, who is now the world.No 12 after her win in Toronto, reeled off four games in succession to level the first set 5-5 after trailing early on to Kerber.
She then broke for 6-5 and took the set a game later.
In the second she began with a break on the way to the win.
“I don’t need to adjust my goals because I don’t set them like particularly for the ranking,” she said.
“I just look from match to match. I would never expect to be number 12 right now.”
Elsewhere on Tuesday, Sloane Stephens took down another seed as she beat number 10 Carla Suarez Navarro 6-1 6-2.
France’s Kristina Mladenovic overcame Daniela Hantuchova 6-2 6-1 while Flavia Pennetta defeated former Australian Open finalist Domenika Cibulkova 7-5 6-2.
Former world No.1 Victoria Azarenka reached the second round after a 6-1 6-2 win over Lauren Davis.
But the Belarus player hinted at a non-critical medical issue which she refused to specify, only to say that she is now working with doctors to deal with it.
“I would just like to keep it for myself at the moment. I’m fine, I’m not in danger. I’m not sick or something,” she said, explaining her recent poor run of results.