World number four Gauff committed 21 double faults as holder Sabalenka fought back from a set down to win 1-6, 6-4, 6-4.
Gauff's struggles echoed those of Sabalenka's, who was often her own worst enemy on serve and previously led the WTA Tour for most double faults before employing a biomechanics trainer and finding a degree of consistency in 2023.
"I was playing that match thinking, 'Well, girl, I feel you. I feel you like nobody else'," Sabalenka told reporters.
"I know what she's going through. This is really tough. But I know that if she'll be able to overcome this serve situation, she's already one of the best players, but I'm pretty sure she's going to be one of the greatest players.
"I was just trying to put as much pressure on her as I could so she would go even crazier on her serve. She just dropped her level on her serve. I just felt like, 'Okay, I still have some chances in this match'. I was pushing myself so hard to put balls back on the other side as much as I could."
Sabalenka, who won the last two editions of the Wuhan Open, faces Olympic champion and local hope Zheng Qinwen in the final and the Belarusian said she was not expecting much support from the crowd at the Wuhan Gymnasium on Sunday.
"This tournament feels like playing at home. Being the third time in the finals, hopefully I'll get this beautiful trophy tomorrow," the world number two added.
"But no expectations on support from the crowd. I have my team. I have my family. I have a lot of people who support me around the world. I'll just focus on that."
