MADRID, Spain - On the day her 16-match clay court singles win streak came to an end, Sara Errani made sure Wednesday wasn't a total loss in advancing to the Mutua Madrid Open doubles quarters alongside Roberta Vinci.

Errani and Vinci's 61 63 defeat of Anastasia Pavlyuchenkova and Lucie Safarova made them 24-4 on the year. With titles in Monterrey, Acapulco and Barcelona and runner-up showings at the Australian Open and Miami, they rank second behind Liezel Huber and Lisa Raymond in the race to qualify for one of the four spots at the WTA Championships. Next up for the fifth-seeded Italians is the team that eliminated Huber and Raymond in the second round - Dominika Cibulkova and Janette Husarova.

Also moving on comfortably were No.7 seeds Yaroslava Shvedova and Galina Voskoboeva, 63 62, over Anabel Medina Garrigues and Arantxa Parra Santonja. The Kazakhs will play No.4 seeds Maria Kirilenko and Nadia Petrova in Thursday's quarterfinals.

Last year's Madrid runners-up, Kveta Peschke and Katarina Srebotnik, were given all they could handle by Julia Goerges and Samantha Stosur but held on for a 62 36 107 victory. In the final eight, they will square off with Nuria Llagostera Vives and María José Martínez Sánchez, who were 64 64 winners over Hsieh Su-Wei and Zheng Jie.

Llagostera Vives and Martínez Sánchez came into this week having not paired up since the 2011 Australian Open. But the Spaniards look to be in the same form that took them to nine titles between 2008 and 2010. In fact, their first round triumph on Tuesday was their 100th career win together, making them one of 10 duos made up of active players with at least that many:

Raymond & Stubbs: 315-122 (72.1%)
Black & Huber: 240-61 (79.7%)
Zheng & Yan: 176-88 (66.7%)
Williams & Williams: 148-19 (88.6%)
Raymond & Stosur: 144-37 (79.6%)
Black & Stubbs: 108-39 (73.5%)
Peschke & Srebotnik: 108-36 (75.0%)
Benesova & Zahlavova Strycova: 106-57 (65.0%)
Dulko & Pennetta: 102-34 (75.0%)
Llagostera Vives & Martínez Sánchez 101-39 (72.1%)