In a tie where Cosmos were wasteful, new Bucs signing Tokelo Ranti netted an 87th minute winner after Isaac Chansa's (45) penalty cancelled out Siyabonga Nontshinga's 29th minute effort for bottom-placed Ezenkosi.
The win lifted the Premiership champions to fifth in the standings ahead of Wednesday's visit of joint-second Moroka Swallows.
"Firstly, it was very important to win here and get three points to improve our position in the log," Leal told the league's official website.
"It came at a good time. It was an away game and I think the team adjusted very well."
The Brazilian added: "In the second half, I think we improved, we put a little bit of pressure. I think when we changed and put players like (Tlou) Segolela, we became more aggressive.
"It was important to win because we know how good Cosmos is. I have been following them very well."