Number five seed Li Na is through to the quarter-finals of the US Open after beating Jelena Jankovic is straight sets.
The 31-year-old was in good form from the off as she got the better of the number nine seed in the first set despite being broken twice by the Serb, winning 6-3.
Li dominated the second set with some imperious groundstrokes as Jankovic had no answer for her power on the court.
The Chinese secured her place in the last eight with 6-0 victory in a set that lasted just 25 minutes and will now play Ekaterina Makarova in the last eight.
