Then in the 75th minute, Barba chased a Jonathan Wright kick to score arguably the try of the season.
The ball bounced on and was destined to go dead before Barba, with his feet millimetres inside the chalk, showed no regard for self-preservation, plummeting head-first for the ground and somehow forcing the ball inside the line.
After several looks video referee hit the green light and the Knights were left to contemplate how they relinquished a 22-6 halftime lead and perhaps their season.
It was Newcastle's third straight loss, loosening their grip on the playoff spot that looked safely in their keeping a month ago.
Had they won, the Knights would have forced South Sydney to beat Brisbane at Suncorp to be any realistic chance of staying alive.
Now the Bunnies have two bites at completing a stunning revival.
Newcastle got off to the perfect start when five-eighth Kurt Gidley scored off a Jarrod Mullen bomb, before booting back-to-back penalty goals.
Richie Fa'aoso and Zane Tetevano also crossed to set-up the healthy halftime lead.
Canterbury completed just five sets in the opening 40 minutes; Sam Kasiano, Andrew Ryan, Aiden Tolman and Gary Warburton all turning over cheap ball inside their own 30 metre zone to gift Newcastle points.
Some sections of the 10,257 crowd even booed the Bulldogs from the field at the break.
Josh Morris streaked away for Canterbury in the first half and Steve Turner finished off a backline play at the start of the second term to ignite a 'Dogs revival.
In the 48th minute hooker Josh Reynolds scored a brilliant solo try for the home side, when he ran cross-field out of dummy-half before slicing through.
Ten minutes later some brilliant quick passing from Kasiano and Kris Keating saw halfback Trent Hodkinson loop around, throw a dummy and break through before finding Jamal Idris - bringing the 'Dogs within two points.
Canterbury are still a minuscule chance of making the playoffs - they would need Souths to lose to Brisbane, and hope that the Knights and Bunnies draw next week, or themselves smash Canberra by a record score in the last round next weekend.
CANTERBURY 32 (B Barba 2 J Idris J Morris J Reynolds S Turner tries S Turner 4 goals) bt NEWCASTLE 22 (R Fa'aoso K Gidley Z Tetavano tries K Gidley 5 goals) at ANZ Stadium. Referee: Matt Cecchin, Adam Devcich. Crowd: 10,257.
- AAP