The Hurricanes left Christchurch with all five points following a see-saw encounter with the Crusaders, winning 29-26.
Kieran Read's 100th game for the Crusaders came to a disappointingly early end, as he watched his side bring themselves back into the contest before Alapati Leiua struck with a stunning try to secure the bonus point.
The Crusaders did show an impressive resolve in the way they came back from an early 17-3 deficit, but the aura surrounding the most successful side in Super Rugby history has gone.
A touch of fortune helped the visitors for their first try, with Julian Savea bumping off Read and his offload going back of a Crusaders' hand before Faifili Levave scooped up and powered his way over after ten minutes.
That try, added to Barrett's penalty, gave the Hurricanes a perfect 10-0 start in as many minutes.
Momentum was all with Mark Hammett's team during the opening quarter, with the Hurricanes running tirelessly as Barrett and TJ Perenara dictated play.
Tom Taylor hit back with a penalty after James Broadhurst was pinged for holding on but the Crusaders were at risk of being cast adrift on the scoreboard when Perenara went over for the 'Canes second try after spotting a gap at the ruck.
The Crusaders needed an inspiration at 17-3 down and it came from Ryan Crotty. The captain, with Read now off the field, surged into the opposition 22 after Andy Ellis took a quick tap, before feeding McNicholl for the first of his two tries with a well-weighted grubber kick.
McNicholl then completed an unlikely turnaround on the scoreboard when he went over for his second score, hard work from the pack upfront making the space out wide for Slade's long pass to find the speedster.
Taylor's penalty before the break gave the Crusaders an 18-17 lead - fitting as two of the last three meetings between these two sides have been settled by one point.
Savea's night wasn't all about power, the All Blacks wing producing a perfectly executed chip and chase for his try and the Hurricanes third to restore their lead at the beginning of the second half.
A solid 20-minute period of pressure from the Crusaders followed, but the home side just couldn't get the breaks when it mattered.
Desperate turnovers from Conrad Smith and his men kept the home side out but it couldn't last forever, Slade darting over in the corner and Taylor eventually adding his third penalty from a ruck infringement against the Hurricanes - much to the delight of the Christchurch faithful.
Barrett was unable to counter Taylor's penalty from long-range but the Hurricanes had threatened with ball in hand all game long, so when Barrett missed a far easier penalty from nearer the posts there was still no need for alarm.
Leiua's superb finish stemmed from getting round on the outside of McNicholl and fending off tacklers going through Israel Dagg to put the Hurricanes up 26-29. There won't be many better individual tries this season.
And so it stayed, Taylor missing a penalty attempt to bring the Crusaders back within three.
Instead they slumped to their third loss of the season, while the Hurricanes made it two wins from three and moved off the bottom of the New Zealand Conference on the back of an truly entertaining performance.
Tries: McNicholl 2, Slade
Pens: Taylor 3
Tries: Levave, Perenara, Savea, Leiua
Cons: Barrett 3
Crusaders: 15 Israel Dagg, 14 Nafi Tuitavake, 13 Ryan Crotty, 12 Tom Taylor, 11 Johnny McNicholl, 10 Colin Slade, 9 Andy Ellis, 8 Kieran Read (c), 7 Matt Todd, 6 Luke Whitelock, 5 Sam Whitelock, 4 Luke Romano, 3 Owen Franks, 2 Ben Funnell, 1 Wyatt Crockett.
Replacements: 16 Codie Taylor, 17 Daniel Lienert-Brown, 18 Nepo Laulala, 19 Dominic Bird, 20 Jordan Taufua, 21 Mitchell Drummond, 22 Kieran Fonotia, 23 Nemani Nadolo.
Hurricanes: 15 Andre Taylor, 14 Alapati Leiua, 13 Conrad Smith (c), 12 Tim Bateman, 11 Julian Savea, 10 Beauden Barrett, 9 TJ Perenara, 8 Blade Thomson, 7 Jack Lam, 6 Faifili Levave, 5 James Broadhurst, 4 Jeremy Thrush, 3 Jeffery Toomaga-Allen, 2 Dane Coles, 1 Ben Franks.
Replacements: 16 Ash Dixon, 17 Chris Eves, 18 John Schwalger, 19 Mark Reddish, 20 Ardie Savea, 21 Billy Guyton, 22 Matt Proctor, 23 Marty Banks.
Referee: Nick Briant (New Zealand)
Assistant Referees: Garratt Williamson (New Zealand), Kane McBride (New Zealand)
TMO: Chris Watt (New Zealand)