The teenage French striker was on target 12 minutes from time as a Sunderland side comprising mainly of Under-21s players edged victory against their Segunda Division opponents.
Midfielder Liam Bridcutt played 45 minutes in his first pre-season appearance after recovering from injury, as Gus Poyet gave the youngsters a chance to impress at Estadio Municipal de Albufeira.
Goalscoring opportunities were few and far between in the first half but Martin Smith struck the Recreativo crossbar with a free kick and David Ferguson then fired wide from the edge of the penalty area.
Liam Agnew cleared off the line as the Spanish side probed and Poyet then opted to ring the chances at half-time.
Recreativo defender Hernan Menosse headed against the crossbar as Sunderland lived dangerously but the Premier League club were in front when Charis Mavrias was upended in the area and Mandron smashed the spot kick straight down the middle.
That proved to be enough to maintain Sunderland's 100 per cent record in pre-season, which they will look to continue when they face Nacional at the same ground on Wednesday.