Croudis finished one shot clear of Hayden Robertson (Taieri Lakes) and Jacob Bellamy (St Clair) to record his win.
Robertson (15) has posted some solid scores in tournaments this year and with his good course management and calm approach is lining himself up for senior selection.
The event looked set to be another Southland charity event when Jeremy Hall (Greenacres) equalled the course record with a six-under 66 in the morning round.
He was four under at the turn with birdies at one, three, five and eight and in a faultless round birdied 11 and 15 coming home.
The previous record from the black teeing grounds was held by Mark Andrews (Taieri Lakes), who finished fifth in this year’s gross event.
Hall led at lunch but Croudis, who posted five birdies and a bogey, was only two shots back on 68.
The wheels fell off for Hall, who went from six under in the morning to six over in the afternoon with 78 to finish in fourth place.Croudis played solid golf in the afternoon for a one-over-par 73 for his one-shot victory.
• New Zealander Lydia Ko has finished in a disappointing tie for 19th in her season-opening Women’s Australian Open event in Adelaide, NZN reported.
The world No 1, in 12th place at the end of Saturday’s third round, could only hit an even-par 72 in Sunday’s final round, finishing with an overall score of three under.
She had hit an impressive four under par 68 in Thursday’s first round, but could not back it up in the following three days.The tournament was won by Ko Jin-young, who recorded an emphatic wire-to-wire victory.
Ko produced a meticulous back nine to card a closing three-under-par 69 and head a South Korean one-two finish, with Choi Hye-jin (67) in second place.