With the scores locked at 4-4, the game sprung to life in the 29th minute when Gallen committed the offence when in possession and rucking the ball off his own line.
Debut referee David Munro penalised the NSW skipper for raking his foot back at Beau Henry's face as he attempted to get up to play the ball.
The Titans five-eighth had just tackled him around the legs and hadn't yet cleared the ruck.
Whistleblower Munro said: "That's my job," when Gallen argued he was just trying to get Henry out of the way.
Prince kicked the first of two penalty goals for the night, before playing a support role in one of the most incredible tries of the season for a 12-4 halftime lead.
Prince kicked deliberately over the top for Mead, 20 metres out from the Sharks line, but it appeared certain the ball would bounce over the sideline.
But the flyer stuck one hand out and miraculously grabbed the ball out of thin air, all while managing to tip toe inside the chalk and touch down - for his second try of the night - in the right corner.
Tries to John Morris, Ben Pomeroy and Ricky Leutele kept the Sharks in the match until the final hooter but, in the end, a William Zillman second-half try and Prince's penalties provided enough of a buffer for the Titans to record the first win by any Gold Coast side at Toyota Stadium.
GOLD COAST 20 (D Moore 2 W Zillman tries S Prince 4 goals) bt CRONULLA 16 (R Leutele J Morris B Pomeroy tries N Stapleton 2 goals) at Toyota Stadium. Referee: Gavin Badger, David Munro. Crowd: 6,313.
- AAP