Leeds recorded their first win of the season after coming from behind to seal a bonus-point triumph over Calvisano.
HEINEKEN CUP POOL TWO
Leeds 33 (11)
Tries: Rawlinson, Palmer, Gerber, Stimpson
Cons: Ross 2
Pens: Ross 3
Calvisano 16 (13)
Pens: Kruger 3
Despite struggling to dominate their opponents, Leeds took an early lead with two Gordon Ross penalties and a try from hooker Rob Rawlinson.
But Calvisano went ahead through a Jacobus Van Schalkwyk try and two penalties from Herkules Kruger.
Leeds responded after the break and Tom Palmer, Rayno Gerber and Tim Stimpson all crossed to end their winless run.
Victory marked the end of a traumatic week for the Tykes, who saw director of rugby Phil Davies stand down as head coach.
Davies' decision was in response to the dismal start to the season which saw Leeds lose all eight games in three different competitions.
But the Tykes made a fine start on Friday night and two early Ross kicks put them 6-0 ahead although Kruger responded with three points of his own after some concerted Calvisano pressure.
French referee Eric Darriere left the pitch injured and the change of official did nothing to stop Calvisano's momentum, only a last-ditch tackle from Tom Biggs preventing Cristian Zanoletti from claiming the first try.
However Rawlinson scored from close range to put Leeds 11-3 ahead although Van Schalkwyk crossed after an offload from Fijian wing Apenise Tuta Vovo just before the break.
And Kruger added another three points to raise Italian hopes that Calvisano could record their first win in the competition.
However the break did the home side good and they soon regained the lead after producing slick inter-passing to give Palmer their second try.
Ross added another penalty and Leeds sealed the bonus point when Gerber and Stimpson scored in the last eight minutes.
Leeds rugby director Phil Davies:
"It's been an interesting week for us. I think maybe we'll look back and see this week as a defining moment in the club's history.
"We're going through processes of building confidence and building performance, and we've been looking for that kind of performance all season.
"It's been difficult and we've asked ourselves a lot of questions but I think we've come out in a positive manner and put a terrific performance together. We scored four nice tries and had a lot to be pleased with."
Calvisano coach Andrew Cavinato:
"We played really well during the first half but Leeds showed their quality after the break.
"It's a great problem for Italian rugby because it's nowhere near as strong as English rugby and Leeds showed that in the second half."
Leeds: Stimpson; Rees, Vickerman, Snyman, Biggs; Ross, Marshall; Kerr, Rawlinson, Gerber; Murphy, Palmer; Hyde, Parks, Thomas.
Replacements: Doherty for Rees (55), De Marigny for Ross (79), McMillan for Marshall (79), Isaacson for Kerr (71), Bulloch for Rawlinson (55), Morgan for Murphy (71), Dunbar for Hyde (55).
Calvisano: Vian-Schalkwyk; Nitoglia, Vaccari, Zanoletti, Tuta-Vodo; Kruger, Griffen; Bocca, Moretti, M Castrogiovanni; Ngauamo, Purll; Zaffri, Mandelli, Zanni.
Replacements: de Carli for Bocca, Ghiraldini for Moretti (51), Bernabo for Mandelli (55). Not Used: Cittadini, Muliero, Pratichetti, Patelli.
Referee: Eric Darriere.