Top seed Lindsay Davenport overcame China's Na Li 6-2, 6-2 on Saturday and will face Francesca Schiavone in the final of the Bali International.
Despite not hitting top form, Davenport found enough strong serves and weight of shot to overcome a talented but erratic opponent, who hit too many forehand errors.
"It was the kind of tennis I wanted to play," said Davenport.
"Even though I missed a few balls, I thought I struck the ball well, better than the other nights.
"The first few games I thought I was playing really well and she was hanging in there with me. I knew that she liked to dictate play so I was trying to overpower her and hit the ball hard and not let her have a lot of time," added the American.
Italian Schiavone booked her place in Sunday's final when her opponent, Patty Schnyder, was overcome by the heat and retired with the score at 1-6, 6-4.
Swiss left-hander Schnyder appeared to be firmly in control and did not face a break point until she double-faulted when leading 4-3 in the second set.
Schiavone then held for a 5-4 lead. Second seed Schnyder called for the trainer and placed an icebag on her head while receiving attention.
When play resumed, Schnyder saved two set points but after hit a backhand wide on the third she retired from the match.
"I started to feel unwell at the beginning of the second set, after two or three games," the 26-year-old said.
"I was feeling dizzy and I couldn't co-ordinate what my legs and what my hands were doing. It was difficult to make any quick movements and my serve went off. I felt like a beginner out there.
Schiavone acknowledged that the heat made play difficult at the tournament.
"The humidity is high. You have to change your shirt, you have to drink correct, eat correct, sleep correct," the London-based Schiavone said. "To stay here is wonderful, but you have to follow every step."
