Tomas Berdych in action against Alexandr Dolgopolov during their quarter-final round match at the Sony Open. (AFP/Clive Brunskill)
Berdych blasted 11 aces and had one more service break than Dolgopolov during the one hour, 45 minute match played in windy conditions at the Crandon Park Tennis Centre.
"I handled it quite well," Berdych said. "I didn't start both sets very well. I was not really up in the both sets. I was break down since the beginning of the first set. Then a break down in the second set, so it didn't look that well.
"But I managed, especially at the end of the second set. I held pretty well and that's what I'm very pleased with."
In Friday's semi-finals, Berdych will face either world number one Rafael Nadal of Spain or Canadian Milos Raonic, who were due to play later Thursday. Nadal is a three-time Miami runner-up.
Thanks to his quarter-final victory, Berdych is projected to rise from his current seventh in the world to number five next week.
The Czech already has one title to his credit in 2014, at Rotterdam, and a runner-up finish in Dubai where he fell to Swiss great Roger Federer in the final.
Berdych is seeking a second trip to the final at Miami, where he lost to Andy Roddick in the title match in 2010. He is also a former Wimbledon finalist.
Berdych said winning in Rotterdam boosted his confidence.
"I'm very pleased with that. There's no question about it," he said. "It's really nice feeling to keep winning and keep playing well, and I will try to continue with this."
Dolgopolov was aiming to reach a fourth straight semi-final, having made it to the Rio de Janeiro final last month, followed by semi-final appearances in Acapulco, Mexico and Indian Wells, California.
Dolgopolov said he felt out-of-sorts on the court against Berdych.
"I'm obviously not happy to lose," Dolgopolov said. "I played good and bad and all around the place.
"I had set point in the second set on my serve, so I had chances to go to three sets.
"It happens. I'm happy to finish the series that I have done for the last seven weeks."
Friday's other semi-final sees second-seeded Novak Djokovic against 20th-seeded Kei Nishikori, who upset Federer on Wednesday night.
Djokovic, who won earlier this month in Indian Wells, won this tournament two years ago. He also claimed the title in 2007 and 2011.
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