With the abandonment of Trentham's meeting last Saturday, the two prestige jumps races were transferred to Hastings, resulting in Nelson and McDougal entering a couple of original absentees from the two features.
The Cossack was one of those entered for the rescheduled Wellington Hurdle, with his trainers believing he would thrive on the better surface of his home track.
Under a cool ride from Shaun Phelan, The Cossack settled towards the rear of the field, with Zac Brown setting a solid tempo up front.
At the 800m mark star jumper Tallyho Twinkletoe made his move for the lead. He kicked clear of the field by a couple of lengths turning for home with jockey Shaun Fannin taking a peek over his shoulder to see The Cossack stalking them.
The Cossack drew level with Tallyho Twinkletoe just strides after the final hurdle, with the son of Mastercraftsman continuing his run to win by 1-1/2 lengths over a game Tallyho Twinkletoe, with a further three-quarters of a length back to Aigne in third.
The victory was The Cossack's third consecutive prestige hurdle victory after winning the Great Northern Hurdle (4190m) last October and Waikato Hurdle (3200m) in May.
His connections were duly thrilled with the result and will now need to map out his future racing plans over the coming weeks, with targets on both sides of the Tasman in the mix.
"It was a really good run, he sat out the back and just let them go crazy up front. The other horse (Tallyho Twinkletoe ) did have five kilos more, but it was a great run," McDougal said.
"I imagine he will stick to hurdling at the moment, but we will sit down and talk about things and where he goes."
Stablemate Shackeltons Edge was also a noticeable absentee from Saturday's Wellington Steeplechase, however, he too was entered in the rescheduled edition and rewarded his trainers' faith.
The Wellington Steeplechase proved to be a battle of attrition, with only three of the seven runners seeing out the 5500m contest.
Shackeltons Edge turned for home with a length advantage over even-priced favourite Yardarm. The pair entered a grueling duel down the home straight and only the judge could separate the pair, with Yardarm getting up by a nose over his adversary.
Despite beaten into second, McDougal was over the moon with the heart shown by Shackeltons Edge in what was his second steeplechase start.
"It was a bloody good effort," McDougal said.
"With the track being firmer we thought he would quite like that. It was always a big step-up in distance (after winning his maiden steeplechase over 4000m at Hastings last start).
"His last start run was good, but it was a great run to step-up into that company and do that."Everyone is a bit blown away with what he has done in his last two runs."