Defending champion Coco Gauff faces fellow American Jessica Pegula in the second match in the Stefanie Graf Group on Sunday after Elena Rybakina and Iga Swiatek triumphed on the opening day.
Sabalenka has qualified for the year-end Finals for the past five years but has never won the title. She was runner-up to Caroline Garcia in 2022.
The 29-year-old was imperious against Paolini, who is the only player competing in the singles and doubles tournaments.
Sabalenka hit 11 aces, won 66% of first-serve points and produced 24 winners to outmuscle the agile Paolini.
The pair traded breaks in the first set before Sabalenka powered on, winning six games in a row to close out the opener and take a 4-0 lead in the second.
Paolini got on the board and took Sabalenka to deuce in the next game, but big first serves helped Sabalenka to hold, and Paolini barely threatened from there on.
Earlier, third seeds Erin Routliffe of New Zealand and Canada’s Gabriela Dabrowski began their doubles campaign with a 6-3 7-6 (7-2) win over Russians Mirra Andreeva and Diana Shnaider.
Elsewhere, Canadian 19-year-old Victoria Mboko continued her breakthrough year with a 7-5 6-7 (9-11) 6-2 victory over Spain’s Cristina Bucsa to win the Hong Kong Open.
It is a second title of the season for Mboko after her stunning triumph in Montreal in August.