Jackman piles on agony for Connacht
Dragons 21 Connacht 8
Quinn Roux scored Connacht's only try but the Westerners lost for the second year running away to Dragons as Bernard Jackman claimed the scalp of his former team.
The visitors came into the game having won nine of their 15 previous league games at Rodney Parade, but had a disastrous opening half and Dragons led 21-3 after tries from Hallam Amos and Elliot Dee.
Jack Carty scored a penalty for Connacht, and Ireland lock Roux added a try after half-time but it wasn't enough for a losing bonus point on a shocking night for the visitors.
Jackman's tenure as Dragons coach had gotten off to a tough start with defeats to Leinster and Edinburgh but they struck inside the second minute with a try from Welsh international Amos.
Carty made it ten from ten off the kicking-tee this season, to reduce the arrears with a penalty and they were well in the game. But after a scrum-penalty went against Connacht, the hosts gained the ascendency, and John Muldoon was penalised for not rolling away at ruck-time.
Henson kicked for the corner and when the ball was recycled, Dee crossed for Dragons' second try. Gavin Henson scored the conversion and Connacht were 12-3 behind in the 20th minute.
They could have fallen further behind but Tiernan O'Halloran saved their blushes after a break from Brock Harris.
Henson pushed Dragons 15-3 in front and Connacht were in disarray while they also lost their influential Ireland full-back O'Halloran to injury in the 25th minute.
Caolin Blade saved another certain try before James Cannon was shown yellow for persistent infringements, and Henson continued to build the Dragons lead with another penalty.
There was a massive lack of discipline from the visitors and they could have gone further behind but Henson missed a relatively easy kick.
Dragons had used all of their back-line replacements due to injury by the 34th minute but Henson scored another penalty for a 21-3 lead with four minutes remaining in the half.
The Connacht lineout was performing admirably to keep them in the game, but they trailed by 18 points at half-time - Dragons should have had their bonus point but only had two tries under their belt.
There were three alterations to the Connacht team at the break with Ireland internationals Kieran Marmion and Dave Heffernan both entering the action.
It was a much-improved performance from Connacht and they struck 13 minutes in when Roux claimed the lineout and then appeared at the back of the rolling maul to score what looked like a vital try.
Crucially, Carty missed the conversion 15 metres in from the left touchline but the momentum had shifted and the Dragons defence were stretched.
But Connacht didn't take full advantage of their period in the ascendency and couldn't even do enough for a losing bonus point.
Dragons - Z Kirchner (J Rosser 15) (O Leonard 34); A Hewitt, T Morgan (D Jones 34), J Dixon, H Amos; G Henson, S Pretorius; B Harris (T Davies 75), E Dee (G Ellis 78), L Brown (L Fairbrother 75); R Landman (M Screech 53), C Hill; H Keddie (R Blake 63), O Griffiths, J Benjamin.
Connacht - T O'Halloran (S Crosbie 26); D Leader, T Farrell (E Griffin 59), B Aki, R Scholes; J Carty, C Blade (K Marmion 40); D Coulson (P McCabe 66), T McCartney (D Heffernan 40), C Carey (F Bealham 50); Q Roux (G Thornbury 63), J Cannon; E Masterson, J Heenan (J Butler 40), J Muldoon.
Ref - Q Immelman (South Africa).