World No. 12 CoCo Vandeweghe beat China's Peng Shuai 3-6, 6-3, 6-2 on the opening day's action at the WTA Elite Trophy in Zhuhai, China.
Germany's Julia Goerges also emerged victorious in her match with Magdalena Rybarikova winning 6-1, 7-6(5).
However, fellow countrywoman Angelique Kerber couldn't follow in Goerges' footsteps, as she fell to a 3-6, 6-3, 3-6 defeat to Anastasia Pavlyuchenkova. The Russian victor, who is world No. 14, takes on Australia's Ashleigh Barty next on Wednesday.
Kristina Mladenovic also takes on Rybarikova on Wednesday, along with Sloane Stephens playing Anastasija Sevastova in Wednesday's last match of the day.