Karolina Pliskova's defeat to Anastasia Pavlyuchenkova means that two of the top three seeds are now out of the women's draw at the Australian Open.
Anastasia Pavlyuchenkova beat Sloane Stephens 6-7 (3/7), 6-3, 6-3 to set up a last eight clash with Danielle Collins.
Coco Vandeweghe, who had knocked out top seed Angelique Kerber in the fourth round, defeated Garbine Muguruza 6-4, 6-0 to reach the Australian Open semis
Serena Williams, who is bidding for a record-equalling Open era 22nd Grand Slam title, will face Russian World No. 50 Elena Vesnina in the Wimbledon semi-finals
Jiri Vesely defeated Lleyton Hewitt, who will retire after the Australian Open, 6-3, 6-7 (1), 6-4 before Karolina Pliskova came from 3-1 down in the second set to beat Jarmila Wolfe Gajdosova 7-5, 6-3 at Perth, Western Australia.
Karolina Pliskova and Barbora Strycova beat Russia's Anastasia Pavlyuchenkova and Elena Vesnina 4-6, 6-3, 6-2 at Prague's hardcourt O2 Arena to hand Czech Republic their fourth trophy in five years.
Svetlana Kuznetsova defeated Anastasia Pavlyuchenkova 6-2, 6-1 in the final in one hour 18 minutes.
Anastasia Pavlyuchenkova, defending champion of Kremlin Cup,
Agnieszka Radwanska defeated Barbora Zahlavova Strycova 6-4, 6-4. Venus Williams also progressed to the next round with a 6-1, 3-6, 6-2 win over Anastasia Pavlyuchenkova.
Playing together for the first time after rejoining forces, third seeded Indo-Pak pair recorded a hard-fought 7-6(5) 6-7(2) 10-3 win over the unseeded Dutch-Romanian team in one hour and 41 minutes.
The 6-1, 4-6, 6-3 win over Roger Federer was Lleyton Hewitt's 29th title on the ATP tour but his first since 2010.
The seven-time Grand Sam winner arrived in Auckland from Los Angeles on Friday and said her aim was to reach the final the WTA meet here that starts on Monday.
Next up for World No.3 David Ferrer in Friday's semifinals of this Australian Open tune-up will be countryman and world No. 1 Rafael Nadal.
World number one Nadal has been coached by his uncle Toni since childhood and it's a partnership which has brought 13 Grand Slam titles.
Roger Federer says on Twitter that he and his wife, Mirka, are expecting another child next year. Their twin daughters are named Charlene and Myla.
The 25-year-old from Bilbao, who plays on the lower level Challenger and Futures circuits, was sanctioned on three charges under the Uniform Tennis Anti-Corruption Program (UTACP).
The Indo-Pak pair, who took the world by storm by reaching the US Open final in 2010, will be coming together for the new season, commencing with ATP Tour in Chennai.
Former French and US Open champion Romanian Ilie Nastase says that Roger Federer should not be advised on the proper time to quit professional tennis.