"Behind every great result there’s a great support team," he said, praising the support of wife Miranda, young children Luca (9), Mateo (7) and Camille (4), and father-in-law John Thomson.
Nearly three hours and 42.2km earlier, Mirosa, the 2015 Otago champion and winner of the 2016 Southland Marathon, got away to a fast clip with Jonah Smith.
Mirosa (39) was happy to go with Smith in putting distance between them and the pack behind."I just wanted them to know we meant business."About the 12km mark, Smith put the hammer down and began to pull away.
Mirosa said it was then he decided to just sit things out behind Smith and wait to take his chances if everything came unstuck for the man in front.
Patience paid off for Mirosa as he noticed the gap between him and Smith reducing all the time, until about the 25km mark he had caught up with him.
Gradually he began pulling away, keeping a strong focus on what was required over the final stages of the course.
He was unaware training partner Nic Bathgate was beginning to make inroads for a step on the podium behind him.
Mirosa’s strong mental focus over the final 10km paid off as the marathon course merged with that of the half marathon and 10km competitors.
"Luckily for me there were two bikes ahead of me keeping a clear path through the runners."
Mirosa said a strong mental focus proved key to negotiating his way to the finish inside Forsyth Barr Stadium. He completed the new course in 2hr 38min 38sec.
"My pace was good, but I couldn’t maintain the same pace in town. I knew it was going to be that way.
"A tail wind at the start, like today, makes a big difference right there, so you push really hard and hope for the best at the end. That’s my strategy."
He said a southerly headwind made for a different race altogether, and one that made the work much harder.
Bathgate, in his debut marathon, overcame his concerns about running through a field of half marathon and 10km runners in the final 15km, to cross in second place in 2hr 47min 52sec.
"It’s a huge buzz running into the stadium," Bathgate said.
"Hundreds of students shouting from their flats. It was an awesome feeling."
Both agreed the course changes added to the atmosphere for competitors and spectators alike.
Smith held on to finish third in 2hr 52min 31sec.
There was plenty of heartbreak over the final stages of the marathon course in the women’s section, after Carla Denneny dominated the women’s field throughout only to be overtaken by fellow Wellingtonian Miranda Spencer 500m from the finish line.
Spencer finished in 3hr 15min 31sec and Denneny crossed for second just six seconds behind. Sarah Butcher (Dunedin) finished third in 3hr 24min 26sec.
Spencer (26), a government adviser, was content to run her own race, and after seeing Denneny disappearing into the distance in the first 10km was somewhat taken by surprise when she made contact with her in the shadows of Forsyth Barr Stadium.
"Miranda is an excellent runner. We run together in Wellington. She’s probably a smarter runner than me. She paced herself a lot better," Denneny said.