McEwan finished 7-under par on 277 for a two-shot win over Mark Brooks (Queenstown) and Nick Borren (Windsor) to win the Alex Sime Cup.
McEwan also led the field of 82 in the handicap event to become the first winner of the Ron Timms Memorial Cup, awarded in honour of the club's most successful amateur and club professional for 25 years.
McEwan looked in good form in the Otago strokeplay at Balmacewen three weeks ago but lost the title to Liam Balneaves (Invercargill) after a poor finish.
McEwan started the final round with a five-shot lead and he was not about to repeat that finish as he scored a final round of 71 to stave off any challenge.
Borren finished as bridesmaid in last year's tournament but looked a winner with an opening round of 65 on the par 71 course.
This placed him three shots clear of McEwan, with Thomas Gillan (Arrowtown) a further shot back in third place.
Disaster struck for Borren on Saturday afternoon with a four over 75 while McEwan carded his second 68 for the day to open up a four-shot lead.
Drew Atkins (Russley) came in third on 143 while Brooks finished 2-over for the day.
McEwan shot his third sub-par round yesterday morning while Brooks set the pace with a 67 to tie with Borren for second.
Otago team for Southland Invitational Team to play in teams' tournament on the Otatara course in Invercargill on 7th and 8th of March. -
Mark Brooks (Queenstown), Philip Bungard (Chisholm Park), Duncan Croudis (Otago) , Andrew Hobbs (St Clair) captain), Brent McEwan (St Clair).
Reserve: Hamish Ireland (Otago).
