In the Miami Masters, German fourth seed, Alexander Zverev, beat Spain's Pablo Carreno Busta to win a place in the final.
In a tense first set the Spaniard, seeded 16th, gave as good as he got, initially leading the tie-break, before conceding it 4 - 6 to 20-year old Zverev.
An early break in the second set saw the German pull ahead, a lead which he confirmed with a second break in the seventh game.
He took the match with an ace, and will go on to play John Isner in the finals where he's setting his sights on his seventh ATP Tour title.
Talking about his forthcoming match against Isner, Zverev said:
"It is not going to be easy. He is playing the best tennis of his life so it is going to be great. I am looking forward to it. I am actually quite happy that he is in the final. He is somebody that I grew up with."
Isner dominates del Potro
Earlier, 14th seed John Isner dominated the first set of his match against Argentina's Juan Martin del Potro, taking it 6-1.
He had to work harder for the second set, eventually winning it on a tie-break which ended del Potro's 15-match winning streak.
The victory will make him America's top seed.