The Black Cats took an early lead when Ross Stewart was brought down by U’s defender Lloyd Jones, who was subsequently sent off.
Stewart then converted from the penalty spot before Elliot Embleton doubled the hosts’ advantage with a free-kick.
Cambridge pulled a goal back through Paul Digby, before Stewart added his second, while Nathan Broadhead and Danny Batth also got on the scoresheet.
Here is how the ‘data experts’ at FiveThirtyEight predict the 2021/22 League One table will finish and whether or not Sunderland will be in the playoff picture at the end of the campaign: