Henin also beat Williams in the quarterfinals at the French Open this year and went on to win her fourth championship at Roland Garros. The Belgian star also has U-S and Australian Open wins on her resume but no All-England title.
Williams collapsed on the court with a strained left calf two days ago during her fourth-round win and played against Henin with her leg taped. The two-time champion also had her left wrist and thumb taped up.
Henin will face 18th-seeded Marion Bartoli in the semifinals. The 22-year-old from France beat Michaella Krajicek 3-6, 6-3, 6-2.