Li Na through in Miami

Li Na has defeated Iveta Benesova to make it into the last 16 of the Sony Ericsson Open in Miami, Florida.

In a tough opening set, the world number eight lost an early service break as Benesova took the initiative.

However, last year's French Open winner saved the set by breaking her opponent to level at 5-5 before a final service break saw her win the set 7-5.

Na overwhelmed the Czech in the second as she broke twice to take the set 6-2.