Kadi struck his first two goals of the season inside the first 16 minutes to enable Wits to match Pirates on 44 points on the log, though Pirates are still third on goal difference.
It took Kadi just over a minute to give Wits the lead, though he was helped by some dire defending from Patrick Phungwayo.
The Bucs left back played an awful ball back towards his own goal that left Kadi in the clear, and the Wits forward struck a low shot past Siyabonga Mpontshane, making his first ever start in a Bucs shirt.
Lehlhonolo Majoro started up front for Pirates, and he had a good chance in the 9th minute, played through by a fine pass from Sifiso Myeni. But Majoro couldn’t get his first touch out from under his feet, and Wits cleared.
Wits goalkeeper Moeneeb Josephs then tried to lob the ball over Mpontshane from a free kick inside his own half, but the ball landed safely in the Pirates ‘keeper’s arms.