Devin Toner was the instigator in that move by snatching a lineout and feeding scrum-half Chris Keane who distributed the sweetest of passes to Sexton. Brian O'Driscoll then released Jones on the flank and the former Ireland Under-20 winger completed the move in the corner.
Leinster took that 12-0 advantage into the interval but Treviso, to their credit, fought back with converted tries on 43 and 50 minutes.
The visitors pressed to regain the lead and it was substitute Rob Kearney who gathered a well-worked kick and chase to race clear of the Italian defence. Felipe Contepomi added the points to conclude a positive week's work for the Magners League champions in front of an animated home crowd.
J. Sexton (1 try, 1 conversion), F. Jones / R. Kearney (1 try each), F. Contepomi (1 conversion)
15: Isa Nacewa (Girvan Dempsey, 22) (Rob Kearney, 60)
14: Shane Horgan (Simon Keogh, half-time)
13: Brian O'Driscoll (Eoin O'Malley, half-time)
11: Felix Jones (Gary Brown, 30)
10: Jonathan Sexton (Isa Nacewa, 51)
9: Chris Keane (Paul O'Donohoe, half-time) (Chris Whitaker, 62)
1: Cian Healy (Stan Wright, half-time) (Ronan McCormack, 62)
2: John Fogarty (Bernard Jackman, 60)
3: Stan Wright (Stephen Knoop, half-time)
4: Trevor Hogan (Malcolm O'Kelly, 51)
5: Devin Toner (Cameron Jowitt, 60)
6: Cameron Jowitt (Kevin McLaughlin, half-time)
7: Shane Jennings (Sean O'Brien, half-time)
8: Stephen Keogh (Jamie Heaslip, 62)