Del Potro wins 14th straight match as Cilic falls in Miami

Acapulco and Indian Wells champion Juan Martín del Potro extended his red-hot form to reach the Miami Open quarter-finals, while second seed Marin Cilic bowed out.

World number six Del Potro made it 14 wins in a row by accounting for Serbian Filip Krajinovic in straight sets on Tuesday.

Australian Open runner-up Cilic exited in the last-16 after succumbing to John Isner but fourth seed Alexander Zverev advanced by beating Nick Kyrgios.

Frances Tiafoe returned to upstage Tomas Berdych in their rain-interrupted third-round clash, though the American could not back it up against Kevin Anderson.

DEL POTRO STAYS HOT

"I will try to keep going and see how far I can go."

That is what Del Potro said after extending his winning streak with a 6-4 6-2 victory against 22nd seed Krajinovic.

Del Potro dug himself out of a 4-1 hole in the opening set to keep his hopes of back-to-back-to-back titles alive.

Next up for Del Potro is Milos Raonic in a rematch of the Indian Wells semi-finals.

Raonic - the 20th seed - saw off Jeremy Chardy 6-3 6-4.

CILIC FARWELLS CRANDON PARK

The Croatian world number three was sent packing by Isner 7-6 (7-0) 6-3 inside 87 minutes on Tuesday.

Isner did not face a break point against Cilic in a further boost to his confidence, having arrived in Mexico amid a three-match losing streak.

The big-serving American, who is just 76 aces from becoming the fourth player to reach 10,000, will go head-to-head with Australian Open semi-finalist Chung Hyeon for a spot in the semis.

Hyeon defeated Joao Sousa 6-4 6-3 to reach his sixth quarter-final of the season.

ZVEREV TRUMPS KYRGIOS IN GROWING RIVALRY

The German star moved into the Miami quarter-finals for the second successive year via Tuesday's 6-4 6-4 win against Kyrgios.

Kyrgios - a two-time semi-finalist in Miami - boasted a superior 3-2 head-to-head record over Zverev.

But Zverev won 76 per cent of his service points and did not face a break point in the second set to eliminate the talented Australian.

A two-time ATP 1000 champion, Zverev will lock horns with Borna Coric in the quarters after the Croatian trumped Canadian sensation Denis Shapovalov 7-6 (7-2) 4-6 6-4.