Two-time defending champion Daniela Hantuchova was sent packing from the Pattaya Open, while Maria Kirilenko advanced.
The WTA International tournament in Thailand has been marred by rain and poor weather continued to delay the event on Thursday.
Sixth seed Hantuchova finally got her title defence underway with a 6-1 3-6 6-0 victory over Olga Puchkova in her first round.
She returned after midnight local time Friday for her second-round clash against Nina Bratchikova, but retired while trailing 6-2 3-0 against the Russian.
Russian second seed Kirilenko, who lost to Hantuchova in last year's final, battled past local wildcard Luksika Kumkhum with a 5-7 6-2 6-2 win.
Kirilenko will face countrywoman Elena Vesnina in the quarter-finals after the seventh seed managed to advance through two matches.
Vesnina got through her rain-interrupted clash against Greece's Eleni Daniilidou in two hours and 45 minutes, winning 6-2 5-7 6-2.
The Hobart International champion backed up, overcoming Frenchwoman Mathilde Johansson 6-2 3-6 6-1.
Serbian top seed Ana Ivanovic saw her tournament come to an end against Japan's Ayumi Morita, on the wrong end of a 6-3 5-7 6-3 scoreline.
The clash had started on Tuesday and the third set resumed two days later, with Morita prevailing.
Morita made the most of her upset win, going on to edge her countrywoman and veteran Kimiko Date-Krumm 4-6 6-4 6-1.
German fifth seed Sabine Lisicki disposed of Russian Alexandra Panova 7-5 6-2, while Romanian fourth seed Sorana Cirstea eased past Australian qualifier Anastasia Rodionova 6-0 7-6 (7-3).
Heather Watson, the British eighth seed, was a surprise loser, going down 7-6 (7-4) 4-6 6-2 to Latvian qualifier Anastasija Sevastova.
New Zealander Marina Erakovic was too good for Thai wildcard Varatchaya Wongteanchai 6-3 7-6 (7-4).