No. 1 Serena Williams took the first set 7-5 against No. 9 Li Na in a hard-fought, well-played battle that was won all too easily in the end.
The two played extremely strong tennis through the first ten games, each holding five times with relative ease.
But at 5-5, Li suddenly seemed overwhelmed by the occasion. Leading 40-0, she inexplicably threw in two double faults and three unforced errors to choke away the game and put Serena up a break.
Serena easily held serve in the next game to take the first set 7-5, putting herself one set away from what is looking like the easiest final four at a grand slam in quite some time.