Sensational Stephens turns up the heat on Kerber
American Sloane Stephens needed just over an hour to cruise past former World No.1 Angelique Kerber 6-1 6-2 and reach the Miami Open semi-finals for the first time.
The US Open champion fired her 22nd winner on match point to dispatch the 10th-seeded Kerber and set up a showdown with either Karolina Pliskova or Victoria Azarenka.
The win guarantees that 25-year-old Florida native Stephens will make her debut in the top 10 when the WTA rankings are released after the tournament.
Yesterday's win was Stephens' second straight triumph over a former World No.1 after she defeated third-seeded Garbine Muguruza to reach the quarter-finals on Monday.
Big-serving American John Isner overcame second-seeded Croatian Marin Cilic 7-6(0) 6-3 to advance to the quarter-finals, where he will face South Korean Hyeon Chung, who dominated Joao Sousa 6-4 6-3.
Isner took firm control of the match in the first set tiebreak, where he stepped up his return game to shut out the World No.3 before finally breaking Cilic's powerful serve in the second set and cruising to the win.
Chung needed just over an hour to see off the Portuguese Sousa, who could not find an answer to the 19th-seeded South Korean's relentless all-court game.
Meanwhile, Rafael Nadal is set to make his return from injury in Spain's Davis Cup quarter-final against Germany next month.
The 31-year-old has not played a match since retiring during the fifth set of his quarter-final against Marin Cilic at the Australian Open in January with a hip muscle injury.
The clash between Spain and Germany will take place on Nadal's favoured clay at the Plaza de Toros in Valencia from April 6-8.
Assuming he is fit enough to play in the tie, Nadal will make his first Davis Cup appearance since a World Group play-off victory over India in 2016, when he only featured in the doubles rubber.
Speaking about his number one player, Spain captain Sergi Bruguera said on the Spanish Federation website: "Rafa is getting better and training more. There is still a week-and-a-half to start the matches and there is time."
Nadal will return to action as World No.1 following Roger Federer's second-round loss to Thanasi Kokkinakis in Miami but will need to match his superb results during the clay season from 2017 if he is to hang on to the top spot.
He is joined in the Spain team by Roberto Bautista Agut, Pablo Carreno Busta, Feliciano Lopez and David Ferrer.