Jonathan is accused of roughing up Grace in the back of their ride while trying to get his phone back after she believed she'd caught him texting another woman -- but the driver's testimony paints Grace as the aggressor, not the other way around.

Taking the stand Monday and speaking through an interpreter, the driver testified he kept his eyes on the road as Jonathan and Grace fought in the back of his Escalade back in March, telling the jury he "had a feeling the girl had hit the boy ... because of the way that she was fighting, and the sounds produced."

The driver also testified Grace demanded to see Jonathan's phone, saying ... "The girl became very angry." The driver also said, "He was not doing anything, she was doing it," and that Jonathan was "trying to get rid" of Grace.

It's an interesting twist in the trial ... last week, text messages between Jonathan and Grace were read aloud in court, including a September 2022 exchange where they seemingly referred to some sort of altercation in London.

In the text messages, Jonathan wrote ...  "They will ask you questions, and as I don't think you actually protect us, it could lead to investigation even if you do lie, and they suspect something."

Jabbari then replied, "I will tell the doctor I bumped my head if I go. I'm going to give it one more day, but I can't sleep and I need some stronger pain killers. That's all: why would I tell them what really happened when it's clear I want to be with you."

The car service driver also testified Jonathan and Grace both left his car at one point, arguing outside on a street corner in Manhattan ... and said Majors was "pushing her back into the car to get rid of her."