James Tracy touched down off the back of a rolling maul to give Leinster their first try after 18 minutes, which Byrne converted.
The Italians responded as Sebastian Negri crossed, Paulo Garbisi adding the conversion, but Leinster winger James Lowe went over from close range to make it 17-12 at the break.
Epalahame Faiva put more pressure on the visitors when he powered in a try soon after the restart, only for Garbisi to miss his kick for the extra points.
But the defending champions gritted their teeth and ground out a win in Treviso ?
— PRO14 RUGBY (@PRO14Official) October 10, 2020
In the 56th minute, Leinster were awarded a penalty try when Jack Conan could not apply downward pressure before Byrne dropped another successful penalty.
Although Gianmarco Lucchesi touched down again for Benetton late on to move within five, James Ryan put the result to bed with another try after 78 minutes to secure the bonus point and guarantee Leinster their second win of the campaign.
Big Dev's warmly-received comeback earlier this year has now been forgotten https://t.co/12IXslePp6
— RugbyPass (@RugbyPass) October 8, 2020
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