Nadal, Wawrinka ease into fourth round at Sony Open

Key Biscayne, FL ( - Top seed Rafael Nadal and third-seeded Stanislas Wawrinka both notched straight-set victories Monday in the third round at the $4.7 million Sony Open, the second straight ATP Masters 1000 event.

A three-time Miami runner-up, Nadal barely broke a sweat against Denis Istomin of Uzbekistan, notching a 6-1, 6-0 victory in just under an hour on the hardcourts at Crandon Park.

Next up for the reigning U.S. and French Open champion Nadal will be 14th- seeded Fabio Fognini of Italy, who battled back to beat Spaniard Roberto Bautista Agut, 4-6, 6-3, 6-3.

Meanwhile, Wawrinka sailed into the fourth round with a 7-5, 6-4 triumph over France's Edouard Roger-Vasselin. The 28-year-old Swiss Wawrinka will next face Alexandr Dolgopolov after the 22nd-seeded Ukrainian rallied for a 3-6, 6-0, 7-6 (7-5) victory over Serbian lucky loser Dusan Lajovic.

Wawrinka, who already owns two titles this year, including his first-ever Grand Slam win in Melbourne in January, has made it to the round of 16 just once before at the Sony Open, when he lost in straight sets to Nadal back in 2009.

Seventh-seeded Tomas Berdych downed Portugal's Joao Sousa 6-2, 6-4, while 10th-seeded John Isner registered a 7-5, 6-3 victory over 18th-seeded Nicolas Almagro of Spain. The American Isner will square off with Berdych of the Czech Republic in the fourth round.

Canadian slugger Milos Raonic, this week's 12th seed, moved on with an easy 6-1, 6-2 win over Spaniard Guillermo Garcia-Lopez and will battle Benjamin Becker in the next round after the German lucky loser recorded a 6-3, 7-5 win against Slovenian qualifier Aljaz Bedene.

The winner of the tournament will earn $787,000.