World number one Novak Djokovic extended his winning streak to 20 after battling past Tomas Berdych in straight sets to progress through to the semifinals of the Paris Masters.
The Serbian claimed a hard-fought 7-6 (3), 7-6 (8) win over fifth-seed Berdych in a contest that lasted two hours and eight minutes.
Meanwhile, French Open champion Stan Wawrinka set up a semifinal clash against Djokovic after trouncing Rafael Nadal 7-6 (8), 7-6 (7) in a thrilling contest.
