Top seed Agnieszka Radwanska and Elina Svitolina eased into the quarter-finals of the Connecticut Open on Tuesday.
World number four Radwanska was taken to a 12th game in the first set but dropped just one in the second on the way to a 7-5 6-1 win over Jelena Ostapenko.
Svitolina, meanwhile, needed just over an hour to see off Evgeniya Rodina 6-3 6-1 on the hard courts in New Haven.
Johanna Larsson knocked out seventh seed Timea Bacsinszky in the surprise of the day to move into the second round along with fellow lucky loser Kirsten Flipkens, while Ekaterina Makarova advanced to the last eight.
RADWANSKA SHOWS CLASS
The Polish top seed was pushed in the first set before needing just 27 minutes in the second to reach the quarters of the WTA Premier event.
Radwanska will be hoping for a better showing than last time out in Cincinnati, where she was knocked out in the last eight by Simona Halep.
BACSINSZKY SAYS GOODBYE
The only shock on Tuesday was Bacsinszky's early exit at the hands of Larsson.
The Swiss seventh seed went out in straight sets, failing to make it out of the first round.
FLIPKENS' NICE SURPRISE
With injuries wreaking havoc in Connecticut, Flipkens was called in at the last minute to replace Lesia Tsurenko - another lucky loser who had to pull out from the main draw with a right knee complaint.
"Well, it was a crazy story," Flipkens said when she got the call to play. "There were so many lucky losers, and I only found out at 12:15 today that I was going to play at two o'clock."
BOUCHARD MEETS KVITOVA
Wildcard Eugenie Bouchard will look to surprise sixth seed and two-time defending champion Petra Kvitova on Wednesday, while second seed Roberta Vinci is in action against Ana Konjuh.