Tomas Machac beat Learner Tien 6-3 7-5 to reach his fourth ATP Tour semifinal at the Abierto Mexicano Teicel in Acapulco.
Machac has become the first Czech player to advance to the semifinal at the ATP 500 tournament in Acapulco and the second overall after Jiri Novak in 1996 and 1998.
Macach ha moved up to world number 22 in the ATP Live Ranking.
The first set featured five consecutive breaks from 1-1. Machac went up a 4-3 lead. The Czech earned his fourth break on his fifth set point in the ninth game to close out the first set 6-3.
Machac converted his second break point in the fourth game to take a 3-1 lead. Tien broke back in the ninth game, as Machac was not able to serve out the match at 5-4. Tien held serve at 15 in the 10th game to draw level to 5-5. Machac broke for the sixth time on his first match point in the 12th game.
Machac converted on 6 of his 14 break points, while Tien broke three times on four chances.
Machac set up a semifinal match against Brandon Nakashima, who beat David Goffin 7-6 (7-4) 6-2 to reach his seventh tour-level semifinal and his first at ATP 500 level.
Goffin earned his first break in the opening game, but Nakashima won four consecutive games with two breaks of serve to take a 4-1 lead. Goffin reeled off three consecutive games to draw level to 4-4. Goffin broke in the 11th game to take a 6-5, but Nakashima broke straight back to send the first set into the tie-break. Both players traded mini-breaks twice en route to 4-4. Nakashima won the final three points to close out the tie-break 7-4.
Nakashima saved three break points to hold serve at deuce in the second game before breaking serve in the third and fifth games to take a 4-1 lead. The US player served out the win on his second second match point.
