del Potro, Coric and Anderson book places in Miami Open quarters

Juan Martin del Potro extended his winning streak to 14 matches as he defeated Filip Krajinovic to reach the quarter-finals of the Miami Open.

The world number six’s excellent run of form continued as he fought back from 1-4 down in the first set to beat the 22nd seed 6-4 6-2.

The Argentinian, on the back of his triumph at Indian Wells, improves his record to a career best 20-3 start to the year.

He will now go on to face Milos Raonic, who overcame Jeremy Chardy 6-3 6-4, winning 85% of his first service points and winning a break in the final game to see out the match.

Croatia’s Borna Coric, meanwhile, denied Denis Shapovalov a place in the last eight, beating the Canadian 7-6 (7/2) 4-6 6-4 after two hours, 17 minutes on court.

A 33-shot rally in the third set saw Coric move ahead before three double faults from his 18-year-old opponent gave him the opportunity to seize on two match points.

American Frances Tiafoe appeared on court twice, first to finish off his defeat of Tomas Berdych 6-7 (2/7) 6-2 7-6 (7/1) after rain interrupted play the day before, and then to face Kevin Anderson in pursuit of a quarter-final place.

Anderson proved to be stronger on the day, hitting 22 winners and nine aces to claim the match 7-6 (7/3) 6-4 and set up his fifth quarter-final of the season.

Elsewhere in Miami, second seed Marin Cilic suffered an upset after John Isner advanced to the quarter-final 7-6 (7/0) 6-3. He will be joined by Spain’s Pablo Carreno Busta, who saw off compatriot Fernando Verdasco 6-3 6-3, and Hyeon Chung, who beat Joao Sousa 6-4 6-3.

In a late game, Alex Zverev claimed the final spot in the final eight, topping Nick Kyrgios 6-4 6-4 after the Australian notched up 27 unforced errors compared with just 13 for the German.