(Reuters) - Danielle Collins continued her impressive form in her final WTA season by notching her 12th straight tour win on Saturday, outclassing Greek third seed Maria Sakkari 6-3 6-3 to reach the final of the Charleston Open.

The American world number 22, who won her first Masters 1000 title at the Miami Open last month, will face fourth seed Daria Kasatkina on Sunday, after the Russian stunned number one seed Jessica Pegula 6-4, 4-6, 7-6(5) in the other semi.