Aces continued their recent fine run of form, remaining unbeaten in their last four matches by bagging their first home victory of the season.
Ajax, who were four points behind early leaders Kaizer Chiefs ahead of the weekend league fixtures, went down in their first defeat after seven matches in the campaign.
Mabhuti Khenyeza had the best chance of the opening period, with a thunderous attempt for the hosts shortly after the half-hour mark, but his effort was well saved by Ajax’s acrobatic Finnish goalkeeper, Anssi Jaakkola.
Masina increased the pressure on the visitors in the 65th minute after being set up by Onyekachi Okonkwo, hitting the back of the net to put his side in control.
The home side nearly stretched their advantage in the dying stages, and while Jakkolla denied a shot from Collins Mbesuma, Aces pocked a valuable three points.
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