KRAKOW, Poland: Former world No. 1 Maria Sharapova sent Russia into the semifinals of the Fed Cup on Sunday as she defeated Poland’s Agnieszka Radwanska 6-1, 7-5 to give her country an unassailable 3-0 lead.

The doubles pairing of Anastasia Pavlyuchenkova and Vitaliya Diatchenko later made it 4-0 as they beat Klaudia Jans-Ignacik and Alicja Rosolska 6-4, 6-4.

Following Sharapova’s victory over Urszula Radwanska in straight sets on Saturday, combined with a three set win for veteran Svetlana Kuznetsova over Urszula’s sister Agnieszka, Russia cruised into the last four.

French Open champion Sharapova is playing just her fourth Fed Cup tie since her 2008 debut but in order to make the Olympics next year all players have to make themselves available for the annual women’s team tournament.

“It is a very important win for me,” said Sharapova, who has often been criticized for not playing enough Fed Cup matches.

“Playing for the national team there is always added pressure.”

In front of a partisan home crowd of some 15,000, Sharapova, who recently lost the Australian Open final to Serena Williams, improved her record against the world number eight to 12 wins against just two defeats.

Petkovic fires Germany into Fed Cup semis

In Stuttgart, Andrea Petkovic endured another gruelling three-set marathon to seal Germany’s 3-1 win over Australia on Sunday and put the hosts in the Fed Cup semifinals.

Germany, the 2014 finalists, will face Russia in the semifinals on April 18-19 after Petkovic again dug deep to seal a 6-3, 3-6, 8-6 win over Jarmila Gajdosova with the third set taking nearly an hour.

It was the second time in 24 hours Petkovic was carried to victory by the vocal 4,000-strong crowd in a gruelling tie after Saturday’s victory over Samantha Stosur came down to a 12-10 battle in the third-set after three hours, 13 minutes of tennis.

Having been 4-2 down in the crucial third, Petkovic showed her composure by converting her second match point to seal Germany’s win and keep them bidding for a second straight final appearance.

“I was a bit tired from yesterday, but I always just played it one point at a time,” said a jaded Petkovic at Stuttgart’s Porsche Arena.

“I hope there is Champagne, but beer is also okay.

“We’ll mix in with the fans anyway, the atmosphere was incredible.”

Angelique Kerber had earlier put Germany on the brink of the semifinals with a straight-sets win over Stosur, who has lost both of her singles rubbers in Stuttgart.

Kerber needed just one hour, 27 minutes to see off 2011 US Open winner Stosur to seal a 6-2, 6-4 victory in the third singles rubber.

Having suffered a shock three-sets defeat to Gajdosova in Saturday’s opening rubber, Kerber, ranked 10th in the world, had no such problems against Stosur.