Moses Spandeel opened the scoring after 13 minutes and Hlompho Kekana added a second 20 minutes into the second half to make it two wins from two for Phunya Sele Sele this season.
On the overall balance of play the score was a fair result, but Leopards will be upset with the slack defending that caused their two goals and the fact that they missed a couple of sitters of their own in front of goal.
It was clear from the opening minute that the Leopards defence was going to be tested as Kekana came close to opening the scoring in the first minute when his 18-yard shot just missed the target.
Still, despite their lack of composure at the back Leopards were the first to force a keeper into a save in the 11th minute. After some great individual work, Raymond Monama worked his way into a shooting position 20-yards out from goal, but he saw his effort superbly saved by Patrick Tignyemb.
Two minutes later, however, and Leopards were made to pay for some poor defensive marking as Kekana drove down the right flank and whipped a cross into the box to find Spandeel completely unmarked. The Celtic man made no mistake with a clinical header into the top right-hand corner, 1-0.
Following the goal Leopards tried to fight their way back into the match and they controlled the possession stakes. Still despite, dominating the midfield battle they could not find the right pass in the final third of the field to unlock the Celtic defence.
In fact, Leopards were lucky to only go into the halftime break another goal down when Clifford Mulenga completely miscued a shot from six-yards out when he should have at least hit the target.
The second half saw Leopards with a couple more chances in front of goal, but failure to take them saw them concede a second of their own 20 minutes into the second stanza.
Before that, though, in the 51st minute Masuku came within inches of equalising for the visitors when his 25-yard shot just skimmed the wrong side of the post.
Thirteen minutes later and Celtic did double their lead in a move very similar to their first goal, and again Leopards marking was to blame. This time Mshengu attacked down the right wing and supplied an inch perfect cross for Kekana to head home from 12-yards out, 2-0.
After going a second goal up Celtic seemed content to sit-back in defence and try preserve their lead. Leopards pushed forward in attack, but couldn’t find the break-through as they lost their second league game in as many matches.
Celtic, though, top the Absa Premiership with six points and a superior goal difference to Orlando Pirates, who also won their second league match on Tuesday night beating Platinum Stars.