Del Potro advances in Los Angeles

Second seed Juan Martin Del Potro booked his place in the quarter-finals of the Farmers Classic in Los Angeles with a straight-sets win over James Blake.

The popular American battled hard and took the second set to a tie-break, but ultimately succumbed to a 6-4 7-6 (7/3) defeat.

Next up for Del Potro is Latvia's Ernests Gulbis, who claimed a 6-2 6-4 win over America's Daniel Kosakowski.

It was a bad day for third seed Marcos Baghdatis who lost 6-3 6-4 to Lu Yen-hsun of Chinese Taipei.

There was also a straight-sets win for Ryan Harrison, who beat fellow American Michael Russell 6-3 6-4.