The 23rd seed battled back from 4-6, 1-4 down to move past the Russian 4-6, 6-4, 6-3 and reach the quarter-finals in Indian Wells for the first time.
Elsewhere, Alexander Zverev sent a warning to the rest of the field at the BNP Paribas Open by easily walking past Frenchman Gael Monfils in their fourth-round clash.
The 30th seed rattled the Greek player early on, but Tsitsipas worked his way back into the match to register a 2-6, 6-3, 6-4 victory in two hours and four minutes.
Daniil Medvedev didn't face a break point and converted three of his seven break chances, completing the match in 72 minutes.
Raducanu struggled under the lights on the stadium court in the Southern California desert on Friday with her accuracy and energy level.