Konta, 27, will face Viktoria Azarenka or Kristina Mladenovic in round two after she overcame world number 11 Ostapenko in two hours and five minutes.
The British number one has dropped to 43 in the world after a frustrating 2018 but rallied from a set down to dominate the 2017 French Open winner.
Konta announces retirement from tennis
01/12/2021 AT 11:30
Some typically aggressive hitting from the 21-year-old Latvian saw her claw her way back from a three-game deficit to take the first set in a tie-break.
However, the unseeded Konta regrouped to dominate Ostapenko, only dropping three more games on her way to a second-round appearance in Montreal.


Petra Kvitova beat Anett Kontaveit 6-3, 6-4
Julia Goerges beat Lucie Safarova 2-6, 6-4, 6-3


Sorana Cirstea 3-6, 6-4, 6-4
Venus Williams beat Caroline Dolehide 7-5, 6-1
Maria Sharapova beat Sesil Karatantcheva 6-1, 6-2
Magdalena Rybarikova beat Barbora Strycova 3-6, 7-6(6), 6-2
Alison Van Uytvanck beat Sofya Zhuk 6-1, 6-2
Ashleigh Barty beat Irina-Camelia Begu 6-3, 1-6, 7-5
Karolina Pliskova beat Katerina Siniakova 6-4, 6-4
Kiki Bertens beat Carol Zhao 6-1, 6-2
Anett Kontaveit beat Ekaterina Makarova 4-6, 6-3, 6-1
Anastasija Sevastova beat Aleksandra Krunic 6-1, 6-0
Lucie Safarova beat Daria Gavrilova 4-6, 6-4, 7-5
Julia Goerges beat Timea Babos 3-6, 7-6(3), 6-4
Carla Suarez Navarro beat Naomi Osaka 7-6(2), 6-2
Lesia Tsurenko beat Katie Boulter 6-4, 6-2
Johanna Konta beat Jelena Ostapenko 6-7(6), 6-1, 6-2
Aryna Sabalenka beat Ana Bogdan 6-4, 4-6, 6-3
Konta pulls out of Chicago, Indian Wells with groin injury
22/09/2021 AT 09:30
WTA Cincinnati
Konta knocked out in first round of Cincinnati Open; Norrie also beaten at pre-US Open tournament
18/08/2021 AT 11:04