Simona Halep is through to the quarter-finals of the Miami Open, thanks to a 6-3 7-5 win over Flavia Pennetta.

In a tight first set both players held serve with ease, before Halep earned a break in the eighth game which proved decisive.

Pennetta hit back strongly as she broke Halep in the first game of the second set, but she lost her advantage immediately as the Romanian dug deep.

Both players then produced some fine tennis as they broke each other routinely, until Pennetta took a firm grip and served for the set at 5-3.

However, Halep rallied and won four games in a row to book her place in the last eight.