Having scored just one try in the past two Super Rugby seasons, Slipper was a surprise scorer when he was on the receiving end of an Andy Muirhead offload in the 29th minute on Sunday.
It was his 10th five-pointer in the competition since debuting for the Queensland Reds in 2010.
The try was also the cherry on top for the former Wallaby, as he became the second player to reach the 200-game milestone.
But more significantly, the Canberrans won their first match since 2000 against the Crusaders in Christchurch.
It's the second time in as many seasons the Brumbies have ended a long winless streak in New Zealand, after they snapped their 12-year losing record against the Auckland Blues at Eden Park last year.
Filling the shoes of injured Wallaby Tom Wright (knee), Muirhead provided the spark, assisting Slipper's try and scoring one of his own in the 19th minute.
The Brumbies found a new gear in the second half, scoring five tries including three in the last 10 minutes to put their opponents to the sword.
"We've had a few big milestone wins and it's all building towards something special," Brumbies captain Ryan Lonergan, who was two years old the last time Canberra beat the Crusaders in Christchurch, told Sky Sports NZ.
"It came down to our discipline. We knew the Crusaders were going to be good down here.
"I'm super stoked to be able to do it for big Jimmy in his 200th."
For the Crusaders, their Super Rugby title defence is already in tatters following a shock 25-23 loss to Kiwi rivals the Highlanders last round.
Despite welcoming back All Blacks prop Tamaiti Williams, Fletcher Newell and Will Jordan, they couldn't handle the Canberrans' dominance, coughing up 15 turnovers.
"It's been a frustrating start," said captain David Havili. "We've got to think fast, get back on our feet, and then go from there.
"There were just a lot of mistakes from us. They capitalised when they got a lot of territory in the first half and they finished on top of us in the back end as well."
The Crusaders scored two tries in the first half through Havili and All-Black George Bell after a dazzling chip by Taha Kemara.
But Muirhead, Slipper and Charlie Cale's five-pointers gave the visitors a 19-14 lead at halftime.
Cale planted another try in the second half after a blistering run down the left flank, while Kadin Pritchard added to his tally after pouncing on a favourable bounce from a Declan Meredith kick in the 54th minute.
Sevu Reece and Leicester Fainga'anuku kept the Crusaders in the match but tries from Corey Toole, Liam Bowron, and Rob Valetini sealed the victory.
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