After taking that tiebreaker, there were some shaky moments to come for Radwanska, who blew a 4-2 lead in the second set.
After Li evened the match, Radwanska requested treatment from a trainer, who wrapped the player’s right thigh with white tape and massaged her back.
“My legs are a bit overused,” said Radwanska, who last year became Poland’s first major finalist in 73 years.
She needed eight match points to put away Li, including six in the closing game, which lasted 10 minutes, but Radwanska finally did it, setting up a reunion of sorts with Lisicki, who she faced when they were juniors playing under-12 events.
“Time flies and suddenly we are here playing [the] semi-final of a Grand Slam,” Radwanska said.
In the women’s doubles yesterday, Taiwan’s Hsieh Su-wei reached the semi-finals after she and Peng Shuai of China beat Jelena Jankovic of Serbia and Mirjana Lucic-Baroni of Croatia 6-4, 7-5.
The No. 8 seeds proved altogether more consistent than their opponents, getting more first serves in, making fewer errors and avoiding any double faults.
Hsieh and Peng will face the winners of the quarter-final between No. 16 seeds Julia Goerges of Germany and Barbora Zahlavova Strycova of the Czech Republic, and Shuko Aoyama of Japan and Chanelle Scheepers of South Africa, who are unseeded.
Both Hsieh and Peng have improved on their best-ever women’s doubles performances at the All England Club, Hsieh having reached the third round in 2010 and last year, and Peng making the quarter-finals in 2007 and 2011.
The Taiwanese-Chinese duo claimed the Italian Open in May by defeating No. 1 ranked pair Sara Errani and Roberta Vinci of Italy at the Foro Italico in Rome.
Additional reporting by staff writer