9:22 PM ET
The No. 79-ranked, 34-year-old Lucic-Baroni won the first set and got an early break in the second, before Pliskova had medical timeout and then went on a roll to win the second set and level the match.
After an exchange of service breaks in the third set, Pliskova took a 4-3 lead and Lucic-Baroni had a medical timeout for what appeared to be a leg problem.
She won the next nine points and served out.