Lisicki defeated Kaia Kanepi, 6-3, 6-3, one day removed from upsetting No. 1 Serena Williams, 6-2, 1-6, 6-4, while Radwanska earned a berth by defeating Li Na, 7-6, 4-6, 6-2, to advance.
This will be Lisicki's second appearance in the semifinals at Wimbledon. She reached the semifinals of the tournament in 2011. Radwanska reached the finals at Wimbledon last year earning a runner-up finish to the eventual champion Serena Williams.
Bartoli defeated Sloane Stephens, 6-4, 7-5, to clinch a spot in the semis, while Flipkins defeated Petra Kvitova, 4-6, 6-3, 6-4, to advance.
Lisicki and Radwanska will square off in the early semifinal on Saturday, followed by Bartoli and Flipkins.
With all four Wimbledon semifinalists entered to play the 2013 Bank of the West Classic the event is ensured of hosting yet another Grand Slam quality player field. The tournament already has four-time Grand Slam Champion Maria Sharapova, 2011 US Open champion Samantha Stosur and 2010 French Open champion Francesca Schiavone scheduled to play.
Tickets for the 2013 Bank of the West Classic, which will be held July 22-28 at the Taube Family Tennis Stadium on the campus of Stanford University, can be purchased by calling the box office at 866-WTA-TIXS (866-982-8497) or by logging on to www.BankoftheWestClassic.com.
The Bank of the West Classic, a Premier WTA event, features a 28-player singles draw as well as a 16-team doubles draw with total prize money of $795,000. The event is owned and operated by IMG and serves as the opening women's event of the Emirates Airline US Open Series.
Qualifying will be held July 20-21 and is free to the public.