she defeated Elena-Gabriela Ruse in a close three-set match, saving six match points and reeling off the last three games in a row to book her place in the second round. In the 2nd round she played Lucie Safarova, to whom she lost in straight sets. For the first time in her career Radwańska lost to Karolina Pliskova in the first round of the 2018 Western & Southern Open, bringing their head-to-head to 7–1 against the Czech. Next she played at the Connecticut Open where she lost to Petra Kvitová in the opening round. For the first time in over a decade, Radwańska came into a Grand Slam main draw outside the top 32 seeds. Unseeded at the US Open, she lost to Tatjana Maria, in the first round. Radwańska progressed to the second round of the Korea Open thanks to a two set victory over Bethanie Mattek-Sands. In a clash of two former winners of the Korea Open, 2013 champion Radwańska lost to the 2015 champion Irina-Camelia Begu in the second round. Due to her ongoing struggles with injuries Radwańska withdrew from the China Open tournament, thus ending the season early with a 14-14 singles record. By the end of the season, Radwańska fell to the 78th position in the ranking - the lowest since 2006, when she made her debut in the WTA series. On 14 November 2018, Radwańska announced her retirement from professional tennis. "Taking into consideration my health and the heavy burdens of professional tennis, I have to concede that I’m not able to push my body to the limits required," she wrote on her Facebook account. Fed Cup participation Radwańska participated in the Fed Cup from 2006 to the present. She played a total of 48 Fed Cup matches with 41 wins and 7 losses. For her achievements she was presented with two Fed Cup Heart Awards. "I think it’s great to play Fed Cup," said Radwańska, "I’ve been playing for the last couple of years and I really think it helped my team to go up and, you know, I’m very happy about it and I’m always ready to play". As member of the Poland Fed Cup team Radwańska participated in 2014 Fed Cup World Group Play-offs. In Barcelona she led Poland to a 3–2 win over Spain, which allowed Poland to advance to 2015 Fed Cup World Group for the first time in