Venus Williams came from a set down to see off Andrea Petkovic and set up a Luxembourg Open final against Monica Niculescu.
Romanian Niculescu barely broke sweat to earn a 6-1 6-3 victory over Slovak Daniela Hantuchova in her semi-final.
But it was Williams who had to put in the hardest shift on Saturday as the American battled past German Petkovic 5-7 6-4 6-4 to make her first final in nearly two and a half years.
Petkovic, ranked 182 in the world, was pushing the seven-time Grand Slam winner all the way and even at 4-4 in the decider looked more than capable of upsetting the player ranked 141 places higher.
But Williams stood firm to break Petkovic’s serve and ease to victory in a marathon two hours, 38 minutes.
Niculescu, ranked 70th, reached her second straight Luxembourg Open final with an easy win over Hantuchova.