Federer, Djokovic advance to Shanghai semis

Top seed and defending champion Roger Federer returned to form to beat Japan's Kei Nishikori 6-4, 7-6(4) and reach the Shanghai Masters semi-finals on Friday.

The 20-times Grand Slam winner has produced a series of lacklustre performances in Shanghai, his first tournament since suffering a shock fourth-round defeat by John Millman at the U.S. Open last month.

Yet he made an aggressive start against Nishikori to take a 4-1 lead in the opening set.

Federer held off a late charge from the Japanese to take the opener before recovering from a 4-1 deficit in the second set tiebreak to seal victory.

The 37-year-old will next face Croatian power-hitter Borna Coric, who dumped Australia's Matthew Ebden out of the tournament 7-5, 6-4. Coric beat Federer in the Halle final in their last meeting earlier this year.

Earlier in the day, three-times Shanghai champion Novak Djokovic extended his winning streak to 16 matches after beating South African Kevin Anderson 7-6(1), 6-3, edging the Serb closer to the world number two ranking.

Djokovic, who has won the last two Grand Slams, at Wimbledon and the US Open, is currently world number three, but could move up a spot if he books a place in Sunday's final.

The 31-year-old Serb saved a set point against Anderson in an intense opener, before taking control in the tiebreak.

Second seed Djokovic broke early to take a 2-0 lead when his South African opponent found the net with a backhand.

Djokovic held the advantage to seal the victory and set up a semi-final clash with Germany's Alexander Zverev, who became the fifth singles player to qualify for November's ATP Finals with a 6-4 6-4 win over Kyle Edmund.

"He (Zverev) has improved a lot, and he has established himself as a top player," Djokovic said.

"I think, quite similar in style of play to today's match. Kevin is a big server, big hitter from the back of the court, really aggressive, tall. Sascha (Zverev) is similar to that."

Zverev became the first German to seal a spot in successive years in the season-ending event since six-times Grand Slam winner Boris Becker (1994-96).

Pliskova eases past Boulter to reach Tianjin semis

Top seed Karolina Pliskova overcame a slow start to put away Britain's Katie Boulter 5-7, 6-0, 6-3 in the Tianjin Open quarter-finals on Friday, improving her chances of qualifying for the WTA Finals in Singapore.

Pliskova, currently eighth in the Race to Singapore standings, is battling for one of the three available spots in the season-ending tournament starting on Oct. 21.

World number 101 Boulter, facing a top-10 player for the first time, took her Czech opponent by surprise with two breaks of serve to clinch the opening set.

Pliskova is known for her powerful serve but it was her return game which came to the rescue as she converted nine break points to move past Boulter into the semi-finals.

Earlier in the day, fourth seed Aryna Sabalenka suffered a shock 7-6(2), 7-6(5) defeat by Swiss Timea Bacsinszky, which ended the Belarusian's chances of participating in the WTA Finals.

Having recently returned to action from a serious leg injury, Bacsinszky deployed the full range of her groundstrokes to reach her first WTA semi-final since the French Open last year. The 29-year-old will face Pliskova for a place in the final.

France's Caroline Garcia also booked a spot in the last four after her sixth-seeded opponent Petra Martic retired, trailing 6-2, 1-0.