Eighth-seeded Jack Sock has booked his place in the semi-finals of the ATP event in Washington after a straight-sets win over Milos Raonic.

The big-serving American, beaten in the quarter-finals in the previous two years, saw off third-seeded Canadian 7-5 6-4 in an hour and 25 minutes.

Sock will face Kevin Anderson for a place in the Washington final after the South African veteran ended Yuki Bhambri’s interest in the competition.

Anderson, the 15th seed, defeated Indian qualifier Bhambri 6-4 4-6 6-3.

Fifth-seeded Alexander Zverev of Germany saw off Russia’s Daniil Medvedev 6-2 6-4 and will face Kei Nishikori in the other semi.

Tommy Paul, a 20-year-old American, had three match points in the second set of his match against the second-seeded Nishikori.

However, the Japanese star fought back to prevail 3-6 7-6 (10-8) 6-4 in a match which lasted two hours and 39 minutes.