Bucs are now five points behind Kaizer Chiefs on the Premiership log, although they have a game in hand.
The in-form Phunya Sele Sele came into the match on the back of a four-match winning streak, while the Bucanneers had been handed their first defeat since September 2012 when they lost to Moroka Swallows, and were also perhaps distracted by the upcoming Soweto Derby.
The game got off to a rather cautious start, before Daine Klate’s free-kick created some excitement on 25 minutes. Klate sent the ball into the box and it was pushed out by Celtic’s defence towards Thulasizwe Mbuyane, who struck an effort from range, but in the end it was easy pickings for Patrick Tignyemb.
At the other end of the pitch Lennox Bacela hit a snap-shot from just outside the box, which flashed inches high.
Mbuyane was Bucs’ most threatening player in the first half and he again tested Tignyemb with a shot on 36th minutes, but he was again denied by good goalkeeping.
Pirates were presented with the perfect opportunity to go a goal ahead into the break after Thabo Nthethe conceded a free-kick 20 yards out, but Klate’s set-piece once again lacked the threat needed to break the deadlock.
There was some uncharacteristic miscommunication between Nthethe and Tignyemb at the start of the second half, which Ndumiso Mabena almost took advantage of, but his header was just wide of the target.
In order to stabilise the backline and keep play compact, Clinton Larsen brought on the towering Dominic Isaacs for Bacela in the 64th minute, and Ruzaigh Gamildien joined the fray a few minutes later.
Going defensive was not the most positive of moves for Celtic and they soon found themselves a goal behind when Tlou Segolela was left unmarked in the box and headed home a cross at the near post.
Pirates looked content to keep a hold of their narrow lead and implemented some time-wasting tactics, however that came to bite them as Ntanga came off the bench to nod home a throw-in deep inside stoppage time.