Tshabalala started ahead of Siphelele Mthembu who was the only out-and-out striker on the bench, with first-choice forwards Kingston Nkhatha and Bernard Parker missing out through sickness and an ankle injury respectively.
'Shabba' put in a man-of-the-match display at Cape Town Stadium, and notably teed up Tefu Mashamaite's headed decider with a telling free-kick in the 49th minute.
"I wasn't sure after five minutes and I wasn't sure if I made the right decision," Baxter said of his deployment of Tshabalala.
"If we play against Ajax away and you start with Siphelele then you will pull him off and play Shabba. When set plays become important near the end of the game it could be a big issue.
"We practise the set plays with Shabba on the field and I thought if we are protecting a lead then it becomes an issue.
"A big lad coming on is better then a small one coming off. So that tipped it and Shabba had a great training yesterday. I must say he was magnificent."
Amakhosi's victory saw them set a PSL record of 15 straight wins [two from last season], and they are now 10 points clear of closest rivals Orlando Pirates at the summit after eight matches.