WIMBLEDON, Great Britain -- Poland's Alicja Rosolska and Abigail Spears of the United States sent the biggest shockwave through the Wimbledon women's doubles draw so far, eliminating the 5th-seeded team of Latisha Chan of Chinese Taipei and Peng Shuai of China in the second round, 6-4, 6-4.

Rosolska and Spears have been one of the most proficient teams during the grass-court season, winning the Nature Valley Open in Nottingham for their first WTA title as a pairing. They also reached the final of the Challenger event in Southsea the week prior to Wimbledon.

The Polish/American duo out-aced former doubles World No.1 players Chan and Peng by five to one, and dominated the seeded team on serve overall, winning a whopping 81 percent of points on their first serves.

Rosolska and Spears were up a set and a break before Chan and Peng converted their only break point of the match to level the set at 2-2. But the 5th seeds were broken again at 3-3, and Rosolska and Peng cruised home from there, dropping only one more point on serve en route to the 72-minute victory.

Elsewhere, No.4 seeds Andreja Klepac of Slovenia and Maria Jose Martinez Sanchez of Spain finished their postponed first-round match on Friday, overcoming Romania's Irina Bara and France's Alize Cornet, 7-5, 6-7(3), 6-3. 

Also in the second round, No.6 seeds Gabriela Dabrowski of Canada and Xu Yifan of China outlasted Japan's Shuko Aoyama and American Jennifer Brady, 6-1, 4-6, 6-3.

In another second-round result, No.8 seeds Elise Mertens of Belgium and Dutchwoman Demi Schuurs eased past Russians Ekaterina Makarova and Vera Zvonareva, 6-4, 6-4. Makarova, currently co-ranked World No.1 in doubles, fails to defend the title she won last year with compatriot Elena Vesnina, who is on the sidelines due to injury.

An additional Top 10 team was upset in the second round, as 7th-seeded Chan Hao-ching of Chinese Taipei and Yang Zhaoxuan of China fell to Christina McHale of the United States and Latvia's Jelena Ostapenko, 6-3, 6-2.

The mixed doubles event also kicked off on Friday, and while the 16 seeded teams enjoyed opening-round byes, many teams with star quality were involved in first-round matches. For example, Sloane Stephens paired with fellow American Jack Sock to oust Australian heroine Samantha Stosur and her British partner Dominic Inglot, 6-2, 6-3.

Elina Svitolina of Ukraine, who occupies a space in the WTA singles Top 5 along with Stephens, also had a successful mixed doubles debut, as she partnered Nicolas Mahut of France to a 7-6(4), 7-6(3) win over American Raquel Atawo and Mexico's Santiago Gonzalez. Gonzalez double faulted down match point to cede victory to Svitolina and Mahut just before darkness fell.

Victoria Azarenka and Jamie Murray also thrilled the crowd with a late-day match. The Belarusian/British pair dropped the first set in a tiebreak to Czechs Lucie Hradecka and Roman Jebavy, but came back to win the second set 6-4 before darkness prohibited the match from going any further. The match will be resumed on Saturday at one set apiece.