Anastasija Sevastova and Caroline Garcia breezed into the quarter-finals of the Ericsson Open, but Chang Kai-Chen sprung a surprise at the Jiangxi Open by claiming the scalp of top seed Zhang Shuai.
Second seed Sevastova, eyeing a second title of the year, eased to 6-2 6-3 victory over Elizaveta Kulichkova on the clay in Bastad on Wednesday.
Anna Blinkova was no match for Sevastova in the first round and the Latvian took only 67 minutes to see the back of Kulichkova, who racked up eight double faults and was broken four times in an erratic display.
French Open quarter-finalist Garcia beat Sara Errani twice in the Fed Cup last year and thrashed the Italian 6-1 6-0 in just 54 minutes.
Garcia saved a break point in the first game of the match and the third seed from France won 12 points in a row to take charge of the first set before wrapping up the second to set up a quarter-final clash with Barbora Krejcikova or Kiki Bertens.
Katerina Siniakova will take on Sevastova in the last eight after ousting Arantxa Rus, while Aleksandra Krunic got the better of lucky loser Viktoriya Tomova.
Chang stunned Zhang in the top seed's homeland, coming through a tense first-round battle to win 6-4 6-7 (6-8) 6-4 in Nanchang.
Zhang was seeking a lift after losing in round one at Wimbledon, but lost the first four games of the match and was broken eight times by an opponent ranked 82 places below her.
Third seed Kristyna Pliskova got past Su Jeong Jang 6-3 7-6 (7-4) in the first round and Arina Rodionova marched on with a 6-4 6-2 win over Liu Fangzhou to move into the third round.
Xinyun Han is also through to the last eight, while Tereza Martincova was another winner in round one.