Benjamin Becker sprung a surprise by beating fourth seed Grigor Dimitrov 6-4 7-6 (7-3) on Friday to reach the semi-finals of the Malaysian Open.
Having already ousted one seed in Kuala Lumpur when he got the better of Jeremy Chardy, Becker produced another upset as he saw off a player 55 places above him in the world rankings.
A single break of the Dimitrov serve was enough for the German to take the first set.
And Dimitrov was punished for failing to convert four set points in the second as Becker battled to force a tie-break before reeling off five points in a row to secure victory.
Becker will now face top seed David Ferrer, who claimed a 6-3 6-4 success against Mikhail Kukushkin.
The other semi-final will feature Nick Kyrgios and Feliciano Lopez, after both men came through tough encounters on Friday.
Kyrgios came good at key moments to beat Ivo Karlovic 7-6 (7-4) 7-6 (7-2) in a match predictably dominated by serve.
Only three break points were carved out in the match and all were saved as both men won 75 per cent of their service points.
“I thought he served really well, but I thought I also served really well and looked after my serve,” Kyrgios reflected.
“I thought I stayed composed and today was a really good performance.”
Second seed Lopez lost the first set to Vasek Pospisil in a tie-break but hit back to triumph 6-7 (2-7) 6-3 6-2.
Both Lopez and Kyrgios are aiming to reach their second finals on the ATP World Tour this season.