Steve Johnson clinched two victories in a day to earn a spot in the Aegon Open final against Pablo Cuevas.
American Johnson, seeded sixth for the grass-court tournament in Nottingham, finished his match with top seed Kevin Anderson - which had been stopped due to darkness on Thursday with the South African leading 4-3 in the final set - completing a surprise 7-6 (8-6) 5-7 6-4 success.
That victory set up a semi-final clash with seventh seed Andreas Seppi, which proved much more straightforward as Johnson claimed a 6-4 6-4 triumph.
He will now take on second seed Cuevas, who came from behind to beat eighth seed Gilles Muller 3-6 7-6 (7-3) 6-4 in just over two hours.
After saving break points at at 4-4 in the second set, Cuevas dominated matters in the resulting tie-break before breaking in the fifth game of the decider to reach his first grass-court final.
"Yesterday [against Marcos Baghdatis] and today, I beat some really good players on this surface," Cuevas said. "Gilles' game is perfect for this surface. I'm so happy to win and it fills me with confidence.
"I've done a lot of work on grass. Now I move better and feel much more comfortable. This is my first time playing three or four matches in a week on grass and the feeling is good.
"Coming in, I thought getting one match was already good preparation for Wimbledon. But I had no idea I could play for a final. It's perfect."