Marmion injury mars Connacht's encouraging start
Connacht 29 Dragons 23
Kieran Marmion limped off after 16 minutes, but Connacht were convincing winners on the first night of the Pro12 season at the Sportsground.
Tries from debutant Nepia Fox-Matamua, Danie Poolman and Fionn Carr, along with four Jack Carty penalties, wrapped up the win for Pat Lam's side, who never trailed.
Marmion appeared to pick up a hip injury, which could dampen his chances of an Ireland call-up during the World Cup, but Lam will be delighted to get off to a winning start.
An infringement at the lineout brought the first points of the game to Connacht after five minutes, with Carty on the mark from wide on the right.
Carty added a second four minutes later, before the slow-retreating Dragons pack were penalised for offside midway through the half and Carty easily made it 9-0.
Connacht made the most of their dominance when they drove over from a well-constructed maul; Fox-Matamua was in control at the back and crossed to score for a 14-3 half-time lead.
Dragons' last win against Connacht came back in 2012-13 but they regained a foothold in the game just after the interval when scrum-half Sarel Pretorius burrowed over from inches out.
However, Poolman soon scored in the corner off a first-phase scrum move to stretch the advantage to 19-13.
A fourth penalty from Carty put Connacht in control before hooker Thomas Rhys Thomas barged over for Dragons.
But Carr ran in behind the posts for the insurance try at the death, only for Tom Prydie to give Dragons a deserved bonus point when he landed a long-range penalty in the last action.
Connacht -T O'Halloran (C Ronaldson 76); D Poolman, R Parata, B Aki, M Healy (F Carr 57); J Carty, K Marmion (J Cooney 16); D Buckley (JP Cooney 63), T McCartney, R Ah You (F Bealham 73); Q Roux (B Marshall 55), A Browne; J Muldoon (capt), N Fox-Matamua, E Masterson (E McKeon 62).
Dragons - C Meyer (T Morgan 62); T Prydie, R Wardle, A Warren, N Scott; J Tovey (D Jones 78), S Pretorius (C Davies 65); B Stankovich (P Price 57), T Rhys Thomas (H Gustaffson 62), S Knight (J Harris 55); C Hill, R Landman; N Crosswell (J Thomas 63), N Cudd (J Benjamin 69), E Jackson.
Ref - B Whitehouse (WRU).