During this month, Kim Clijsters announced that she would help her as a part-coach. 2013: Wimbledon semifinalist, breakthrough into the top 15 Flipkens started her 2013 season really well, reaching quarterfinal at the ASB Classic, where she lost from her compatriot Yanina Wickmayer. Next week, at the Hobart International, she defeated Francesca Schiavone in the first round and continued with wins over Bojana Jovanovski and Monica Niculescu, before falling to Mona Barthel in the semifinals. Her next tournament was the first Grand Slam of the year, the Australian Open. She defeated Mandy Minella, Klara Zakopalová, and Valeria Savinykh in the first rounds to advance to the fourth round where she lost 1–6, 0–6 to Maria Sharapova. That was the first time she reached that stage at any Grand Slam tournament. She then proceeded to reach the quarterfinal of the U.S. Indoor Championships, losing there to Magdaléna Rybáriková. At the Indian Wells Open, she got bye for the first round, then beat Monica Niculescu in the second round before she lost from Victoria Azarenka. Next, she reached quarterfinal of the Miami Open, where she also got bye for the first round, and then beating Petra Kvitová in the second round before eventually falling to Agnieszka Radwańska. She started the French Open as 21st seed, and beat Flavia Pennetta in the first round before losing to 2010-champion Francesca Schiavone. She also played in mixed doubles, partnering Colin Fleming, but they lost in the first round. After the French Open, Flipkens reached top 20 for the first time. To prepare for Wimbledon, Flipkens participated in the Birmingham Classic. Top-seeded, with a bye in the first round, she beat qualifier Ajla Tomljanović, before she lost to Magdaléna Rybáriková in the third round. A week later, at the Rosmalen Grass Court Championships, Flipkens advanced to the final but was ultimately beaten by Simona Halep. Flipkens played at Wimbledon as the 20th seed having not even played in the qualifiers the previous year due to her low ranking. She exceeded expectations by advancing to the semifinals of a Grand Slam for the first time in her career, beating Flavia Pennetta in the fourth round and former champion Petra Kvitová with in the quarterfinals. However, she was defeated 6–1, 6–2 by eventual champion Marion Bartoli in the semifinals. During her semifinal match, Flipkens suffered a knee injury, due to which she didn't play for one month. A