He agreed the turning point in the match was when busy Hawke's Bay United forward Tinashe Marowa missed a sitter in the 29th minute. He received a good pass on the Southern United line and tapped the ball into visiting keeper Liam Little's arms when the rest of the goal in front of him was wide open.
Had Marowa capitalised on that opportunity the score would have been 1-all. Fifteen minutes later Coughlan succeeded with a penalty attempt after Hawke's Bay United left back Jorge Akers conceded a soft penalty and it was always going to be tough for the hosts to recover.
Hawke's Bay United finished the season without a win at their Park Island base and coach Brett Angell said today's defeat epitomised their season.
"We conceded soft goals and didn't take our oportunities. The boys didn't concentrate. They were pre-warned on how Southern United were going to play and they didn't take in that information. They recognised it far too late."
Southern United deserved their 2-0 lead at halftime. They had six shots on goal, one more than their hosts during the first 45 minutes and were awarded four corners, one more than Hawke's Bay United.
When the final whistle blew Southern United had 10 shots on goal, one more than Hawke's Bay United and Hawke's Bay United had been awarded six corners, one more than the visitors.
Coughlan opened the scoring for the visitors with a goal in the 20th minute. He found the Hawke's Bay defenders out of position and beat keeper Ruben Parker with ease.
Sixteen minutes into the second half Coughlan had his hattrick when he headed in a superb feed from Conor O'Keefe.
Hawke's Bay United's forwards were guilty of not putting themselves in space and better scoring positions when teammates had the ball. However they never gave up and were rewarded with a consolation goal in the 82nd minute to substitute Sam De St Croix.
Marowa was creative on attack and captain and centre back Bill Robertson again had a huge defensive workrate.
■ Full report - Monday