Serena Williams has thrashed American 15-year-old Catherine Bellis 6-1 6-1 to book her place in the last 16 of the Miami Masters.
Williams allowed just one point against her serve throughout the first set and converted both her break points in game two and six to take the first set in 22 minutes.
It took just a further 20 minutes for Williams to complete the victory, this time conceding two points against her serve.
Bellis won the opening game of the set before losing six on the bounce as Williams progressed.
Williams will play against Svetlana Kuznetsova in the next round.
