Top seed Carlos Alcaraz moved to within two wins of completing the "Sunshine Double" with a 6-4 6-2 victory over Taylor Fritz at the Miami Open on Thursday while Daniil Medvedev ended the dream run of American qualifier Christopher Eubanks.

In a high-quality clash between two players who reached the quarter-final without dropping a set, defending champion Alcaraz never trailed and frustrated the top-ranked American Fritz.

"A little bit of nerves at the beginning of the match, it was new for me playing against him, never played him before," Alcaraz said in his on-court interview. 

"Of course I am really happy with the way that I started the match with no mistakes and with a lot of power. It was a key for me to break the serve at the beginning," he added.

Up next for Alcaraz will be a clash with 10th-seed Jannik Sinner, whom the Spaniard beat in the Indian Wells semi-final to improve to 3-2 in head-to-head meetings with the Italian.

Meanwhile, Medvedev, in the semi-finals in Miami for the first time, will face fellow Russian Karen Khachanov for a place in the final after the 14th seed beat Argentina's Francisco Cerundolo 6-3, 6-2. 

The 26-year-old Eubanks was playing in his first ATP Masters 1000 quarter-final after upsetting Frenchmen Adrian Mannarino and Gregoire Barrere and Croatia's 17th-ranked Borna Coric. The American will move from 119th to 85th in the ATP rankings.

Medvedev has now won 22 of his past 23 matches, capturing titles in Rotterdam, Doha and Dubai during that run and reaching the final in Indian Wells, where he lost to Alcaraz. 

"I have never had such a good start to the season. A lot of matches won, tournaments won. I am really happy," Medvedev said.

In the women's action, twice Wimbledon champion Petra Kvitova beat Russia's Ekaterina Alexandrova 6-4 3-6 6-3 to set up a semi-final clash with unseeded Romanian Sorana Cirstea.

(With input from agencies)