The women's team triumphed first on Sunday, earning their fourth straight win, by less than a length.
And the Cambridge's men followed suit, with victory in the 166th staging of the race by less than a length as well.
The race had been moved from the Thames to Ely in Cambridgeshire because of the coronavirus pandemic.
The narrower Great Ouse river produced moments of drama with Sarah Winckless, the first female umpire in the history of the men's race, repeatedly warning Cambridge cox Charlie Marcus to change his crew's line to avoid a clash of oars.
Cambridge had hit the front early on and held their advantage throughout for their third straight win and a fourth in five stagings.
"I had to be as far over as I could. I never fouled them, so that's what I had to do," Marcus said on BBC One. "About three strokes before the finish was when I thought we had this won."
"You dream of this moment," Cambridge rower Theo Weinberger said. "I don't know what to say, it's two years' worth of training and hard work, it just means so much and I don't think there's anything you can quite compare it to."
In the 75th women's race, Oxford were also repeatedly warned by umpire Judith Packer for encroaching on their rivals' line in a tight race.
But Cambridge held their nerve, having taken a slender lead after halfway.
Dylan Whitaker, the winning cox, was full of praise for his opposite number Costi Levy.
"Massive, massive props to Costi because she steered like an absolute champ. That was close but we knew what our plan was, we kept it calm and loose and it worked," he said on BBC One.
Sarah Tisdall, one of the Cambridge rowers, added: "Awesome race, massive congrats to Oxford. That's the closest boat race the females have had. Awesome day for women's sport and really proud of this team. It's been awesome."
If you really look closely, most overnight successes took a long time.