Marinko Matosevic continued his winning run at the US National Indoor Tennis Championships, at the expense of Alexandr Dolgopolov.
The Australian world number 53 served exceptionally to see off the Ukrainian seventh seed 6-7 (6-8) 6-2 6-4 in just over two hours.
Matosevic, who will resume the mantle of top-ranked Australian over Bernard Tomic on Monday, dropped just three points on serve in the final two sets to cap a dominant display.
Top seed Marin Cilic bowed out at the quarter-final stage, losing comprehensively to fifth seed Kei Nishikori 6-4 6-2.
Nishikori endured 12 aces from Cilic to book a semi-final date with Matosevic, with the Japanese leading their head-to-head record 1-0.
The world number 22 Nishikori won their only previous clash at Brisbane earlier this season in straight sets.
In the other half of the draw, Spain's Feliciano Lopez will meet Uzbekistan's Denis Istomin in the final four after they recorded straight-sets quarter-final victories.
Lopez saw off promising American Jack Sock 6-4 6-3, while Istomin defeated lucky loser Michael Russell 6-4 7-6 (7-5).
The Spaniard leads the head-to-head record with Istomin 2-0, however they have never met on hard court.
In the WTA International event in Memphis, third-seeded German Sabine Lisicki will meet New Zealander Marina Erakovic in the final after they each recorded two-set wins.
Lisicki edged out Slovakian seventh seed Magdalena Rybarikova 7-5 7-5 in one hour and 49 minutes, while Erakovic made a third WTA final in search of her first title, courtesy of a 6-2 6-4 win over Swiss Stefanie Voegele.