At the 2008 Wimbledon Championships, Radwańska made her Grand Slam singles debut, losing in the second round to two-time champion Serena Williams 4–6, 4–6.

Having seen the fight she put up in this match, the commentator Andrew Castle observed: "She is sound in just about all areas, and she knows what to do with the ball, she seems to have an understanding, a little like Martina Hingis."

On 16 February 2009, the Radwańska sisters played their first official tour match against each other in the first round of the Dubai Tennis Championships.

In the second Grand Slam tournament of the year, the French Open, Radwańska lost in the first round to Yanina Wickmayer.

At the US Open, she scored her first main-draw win of the year by defeating Anna Chakvetadze, but lost her next round to Lourdes Domínguez Lino.

Subsequently, she won three qualifying matches at the US Open to make the main draw before she lost to her sister Agnieszka in the first round.

She reached her first WTA Tour semifinal at the Tashkent Open, eventually losing to top seed Ksenia Pervak.

[2] Ranked 99 at the Australian Open, Radwańska defeated qualifier Alison Riske in the first round, before losing to Sorana Cîrstea 6–1, 2–6, 3–6.

She started out the summer hardcourt season at the Silicon Valley Classic and Southern California Open where she reached the quarterfinals of both events.

Returning to hardcourts, she qualified for the main draw at Rogers Cup and Western & Southern Open where she lost to Ekaterina Makarova and Serena Williams respectively.

[10] Radwańska won her first tour match of 2013 at the Qatar Ladies Open defeating Nadiia Kichenok in the first round.

[13] Radwańska qualified for the Dubai Championships beating Yuliya Beygelzimer, Akgul Amanmuradova, and Kurumi Nara.

[14] In March, Radwańska played at the Indian Wells Open where she beat Arantxa Rus in her first-round match.

[18] She played at the Miami Open where she won her first-round match over Annika Beck but then lost to 12th seed Ana Ivanovic.

[25] Ranked 40 at the French Open, Radwańska stunned 30th seed and seven time Grand Slam champion Venus Williams in the first round.

Seeded eighth and receiving a first-round bye, she was defeated in the second round by eventual finalist Donna Vekić.

[29] Ranked 44 at the Wimbledon Championships, Urszula lost in the second round to American wildcard Alison Riske.

She won comfortably over Christina McHale and Daniela Hantuchová, before losing in the quarterfinals to third seed and eventual champion Dominika Cibulková.

[40] At the Abierto Mexicano, Radwańska was defeated in the first round by top seed and eventual champion Dominika Cibulková.

[43] The week after, Radwańska played at the Monterrey Open where she lost in the first round to second seed and eventual champion, Ana Ivanovic.

[44] During the Fed Cup Play-off tie versus Spain, Radwańska lost both of her rubbers to María Teresa Torró Flor and Silvia Soler Espinosa.

[47] Starting her grass-court season at the Birmingham Classic, Radwańska was defeated in the first round by 16th seed Casey Dellacqua.

At the Wimbledon Championships, Radwańska was defeated in her first-round match by ninth seed Angelique Kerber.

In July, she took out the last seed standing, Tsvetana Pironkova, to reach her first WTA semifinal in almost three years at the İstanbul Cup.

It was a disappointing outcome for Radwańska, who was also defeated on her only previous appearance in a WTA Tour final, in Rosmalen three years ago.

[51] In August, Radwańska participated in the US Open, but fell to Magda Linette in the first round and ended the season ranked No.

She continued at Taiwan Open, where she defeated Hsu Ching-wen but lost to Venus Williams in the second round.

[53] In addition to her tennis career, Urszula Radwańska is also a businesswoman, and created and now owns the UR brand of luxury handbags.