Celtic had the first two shots in anger, with Hellings Mhango and Musa Nyatama both driving efforts on target inside the opening 10 minutes, only for goalkeeper Daouda Diakite to save on each occasion.
The team in green and white continued to control the game after those early shots, but it was Stars who opened the scoring 10 minutes before the break.
Sekola got on the end of Thabo Moloi’s pass to beat goalkeeper Bongani Mpandle with a right-footed finish for his 13th of the League campaign.
Celtic responded well to going behind and almost claimed an equaliser in the 40th minute. Mhango shot direct for goal from a free-kick, but it went inches wide.
The home side continued to threaten an equaliser in the early minutes of the second half, while Sekola almost claimed a second goal for Ea Lla Koto in the 57th minute when he headed over from another Moloi cross.
Celtic created further chances to equalise, but the visitors held them at bay to claim a fifth successive League win and move to 37 points with one fixture remaining. Celtic remain on 40 points.
Stars host Black Aces and Celtic travel to Moroka Swallows for their final matches of the season on Saturday.