Swiatek, seeded second, is aiming to become the first woman to win the tournament three times and the Polish player looked eager to do so in as little time on court as possible on Sunday (Monday AEDT), reeling off 10 games in a row and needing just 65 minutes to see off her Ukrainian opponent.
"At the end I got a bit tired, it's always hard to finish a match like that but I'm happy that I kept my intensity up in the last game to close it," she said.
"I had control from the beginning so I'm happy with the performance for sure."
It was Swiatek's second bagel set of the tournament after she overwhelmed Caroline Garcia 6-2 6-0 in her first match.
The five-time major champion has not won a title since her triumph at Roland Garros in 2024, her longest drought since winning her first slam in 2020.
She served a one-month suspension in October for a failed drug test and has seen Aryna Sabalenka take her world No.1 ranking, but said the California desert is an ideal setting to get back to winning ways.
"It's amazing, I love coming here," she said.
"I already have my routine so it feels like home. It's for sure the place to be and a great place to play tennis."
Swiatek will face 15th seed Karolina Muchova in the round of 16 after the Czech beat her compatriot Katerina Siniakova.
After cruising through the first set, Rybakina fell behind 5-3 in the second before regrouping.
She stretched to hit a sensational defensive shot in a game where she broke back for 5-5 and broke again on match point to seal the win.
Rybakina, who missed last year's tournament due to an illness, will next play ninth-seeded Russian teenager Mirra Andreeva, who served up yet another bagel while crushing Denmark's Clara Tauson 6-3 6-0.
The clash is a rematch of their Dubai semi-final, which the Russian won in three sets en route to becoming the youngest player to win a WTA 1000 title.
In other results, American fourth seed Jessica Pegula thrashed China's Wang Xinyu 6-4 6-1 to set up a clash with 23rd seed Elina Svitolina, who downed 14th-ranked Danielle Collins 6-2 6-4.
Another Ukrainian in Marta Kostyuk beat American wildcard Caroline Dolehide 6-3 6-3.
In the late match, China's eighth seed Qinwen Zheng was made to work hard before beating New Zealand's world No.49 Lulu Sun 6-4 7-5.
With AAP.
