The Sharks stayed in the contest and nearly looked like forcing victory for Johnson, particularly when the former long-serving Warriors halfback helped forge a 12-2 lead.
He was at his best in putting Briton Nikora across, the beaming smile on the face of the off-season club-hopper possibly explaining the deluge of boos that preceded his successful conversion.
Another former Warriors halfback had his moment soon afterwards when Townsend crossed, although it was in contentious circumstances.
Matt Moylan’s offload found a juggling Bronson Xerri who batted the ball to Townsend. Both transfers hinted at being forward.
The Sharks barely visited the Warriors zone for the next 50 minutes but all the hosts had to show for it was a slick converted try to Green and a penalty to Issac Luke.
Match officials were back in the spotlight when Sosaia Feki crossed via what appeared a blatant forward pass from Nikora before cleverly controlling the grounding behind his back.
Kodi Nikorima busted through and dragged Moylan over the line to reduce Cronulla’s lead to 18-16 and the scores were level when Andrew Fifita had a brain explosion.
The Sharks prop shoulder charged Lachlan Burr without the ball, earning 10 minutes in the sin bin and gifting two points that set up the dramatic finish.
NZ WARRIORS 19 (B Green K Nikorima tries I Luke 3 C Harris-Tavita 2 goals B Green field goal) bt CRONULLA 18 (S Feki B Nikora C Townsend tries S Johnson 3 goals) at Westpac Stadium. Referees: Henry Perenara, Phil Henderson. Crowd: 14,295.