The Spaniard scored two goals during the Black Cats' 4-0 win over Wednesday in August and he grabbed both, including a contentious opener, on Friday night to help his side move within five points of second-placed Sheffield United.
The hosts had an early penalty appeal waved away before Mayenda opened the scoring after 34 minutes.
A hopeful long ball from Leo Hjelde was misjudged by Max Lowe and controlled by the arm of the forward, before his scuffed effort was deflected past the onrushing James Beadle and into the net.
Ex-Bournemouth player Chris Mepham's indecision gifted an equaliser for the hosts as Callum Paterson headed home three minutes after the restart, but Mayenda's header from a brilliant Trai Hume cross in the 71st minute ensured Sunderland returned to winning ways after successive league defeats.
Danny Rohl reiterated his belief for VAR to be utilised in the league after the controversial loss.
"I think I've made my clear statements over the last three weeks," Rohl said when asked where VAR should be introduced in England's second tier.
"What we should do is help the refs on the pitch, especially now I think every week we have a big, big decision against us.
"Two easy conceded goals and then two big decision against us, and in the end we stay here and lose 2-1.
"Before the 1-0, there is a handball, a handball in the box from the opponent, but the ref doesn't see it.
"Everybody will see it, everybody could see it, but I can't decide the situation. This is maybe why we need support for refs on the pitch."
Sunderball boss Regis Le Bris hailed a valuable triumph which saw the Black Cats remain in fourth.
"It was a really important win this evening because after two defeats we had to react and I think we showed character," the Frenchman said.
"Our only goal is to win games and after that, we will see (how) the dynamic of the top three (will play out)."
