The former Seattle Sounders youngster joined the Swedish outfit on a one-half-deal this month and was granted work permit last week.
Mansaray, who was introduced in 58 minutes replacing Mikael Wikström, was expelled five minutes later but Umeå was resilient enough as they managed a 3-1 win over Sollentuna.
Mansaray, 20, hasty tackled on an opponent ended his debut day on a sad footing leaving his team to play for over 30 minutes with a man down, but perhaps a harsh decision by the referee.
A brace for Swedish striker Mikael Wikström in the opening 15th minutes laid a strong foundation to a 3-1 victory.
The visitors pulled a goal back through Brwa Pishdari to make it 2-1 before Dillian Ismail restored Umea’s two-goal lead from the penalty spot.
The victory means they’re comfortable in second position on the Norra div standings four points behind IK Brage and they take on Team TG on Friday, September 1 and Mansaray will not be available due to his suspension.
Umeå FC – Sollentuna FF 3-1
Goal: 1-0 (8) Mikael Wikström, 2-0 (14) Mikael Wikström, 2-1 (18) Brwa Pishdari, 3-1 (23) Dillan Ismail (penalty).
Warnings: Umeå FC: Mikael Wikström (11), Tobias Sandström (41), Zach Sekunda (56). Sollentuna FF: Sotirios Nikopoulos (18).
Expulsion: Umeå FC: Victor Mansaray (63).
Connect with us @football_sierra, on Facebook/ Instagram Football Sierra Leone, the writer @bittar32 Contact email@example.com.