Memphis, USA, 23 February 2013 | AFP

Australian No.2 Marinko Matosevic is through to the semifinals of US National Indoor Tennis Championships courtesy of a straight-sets win over seventh seed Alexandr Dolgopolov.

Matosevic’s impressive run in the tournament continued on Friday with a 6-7(6) 6-2 6-4 victory over the Ukrainian, after he defeated Japan’s Go Soeda and fourth-seeded American Sam Querrey in the earlier rounds.

The Victorian finished with a sparkling 11 aces to no double faults and won an impressive 87 per cent of points behind his first serve, making it difficult for the world No.23 to impose his flashy game.

The win sends Matosevic into his first semifinal since reaching the last four in Los Angeles last July, and is his best result ever at ATP 500 level.

In the semifinals, world No.53 Matosevic will meet Kei Nishikori, who won their only prior meeting in Brisbane earlier this year.

Fifth-seeded Nishikori of Japan cruised past top-seeded Marin Cilic 6-4 6-2.

Croatia’s Cilic had saved three match points in his previous match against Igor Sijsling, but couldn’t find the answer against Nishikori, who had just four aces compared to a dozen for Cilic but won 69 per cent of points on his serve.

“I was dominating with my serve,” said the 23-year-old Nishikori, who reached the semifinals in Brisbane in January but retired from that match against Andy Murray with a knee injury.

Since then, he has reached the fourth round of the Australian Open.

“It’s getting better every match … little by little,” Nishikori said of his game.