The Chilli Boys defeated Sundowns 2-1 in Port Elizabeth on Saturday for a second straight win under new coach Clinton Larsen.
Larsen, who replaced Joel Masutha at Chippa, started his reign at the relegation-threatened club with a 2-0 league victory over bottom-placed Maritzburg United earlier this month.
"Two wins in a row ... this is the first time this season," said Mayambela, who came on as a substitute against Downs at Nelson Mandela Bay Stadium.
"It's a good win, not only for the league and improving our position on the log but it also added much-needed confidence going in to our upcoming fixtures."
The former Orlando Pirates midfielder gave credit to Larsen for getting immediate results since relocating to the Eastern Cape.
"He has worked more on the psychological and tactical part of our game.
"He has identified our weaknesses in both phases of the game and what he wants us to improve."
Larsen's side next visit fellow strugglers Baroka in the league in Limpopo this coming Sunday.