The win was a perfect send-off for former All Black Aled de Malmanche, who played his last game in Waikato colours before leaving for Stade Francais.
De Malmanche, who can play hooker and prop, was in the thick of the action as he led his side upfront with a damaging shove at scrum-time that had Counties backpedaling throughout the match.
Waikato's win see's them rise above Auckland on the Premiership table while Counties sit at fifth on the Championship table after picking up a losing bonus point.
With Donald and Kerr kicking three penalties apiece in the opening stanza, the match was at a 9-9 stalemate at the halftime stage.
Immediately from the kickoff the Steelers were on the backfoot as Waikato won the ball and halfback Brendon Leonard stepped past Simon Lemalu to run deep in to their 22.
Centre Save Tokula made a half-break and offloaded to Zac Hohneck who went to ground before replacement prop Latu Talakai powered over from a metre out for a try in the 42nd minute.
Donald converted from beside the uprights to give his side some breathing space at 16-9.
Counties were never going to let their neighbours slip-away from their grasp, and Kerr's fourth penalty brought his side back within a try of the lead at 16-12.
The two number tens went penalty-for-penalty to take the score to 19-15 and setup a tense final ten minutes as Counties looked to snatch a late-win.
The game had been dictated by the boot of Donald and Kerr and the former All Black had the last say with a penalty from 40 metres to push his side out of reach with five minutes remaining.
Waikato 22 (Latu Talakai try; Stephen Donald 5 pen, con) Counties-Manukau 15 (Baden Kerr 5 pen). Halftime: 9-9.
- HERALD ONLINE