Wing Fetu'u Vainikolo dashed over for a brace of tries as Connacht closed the gap on Italians Treviso with an excellent away RaboDirect Pro12 victory over Newport Gwent Dragons.

Connacht have been the perennial poor relations to Ireland's big three provinces but they looked anything but that at Rodney Parade where a top first-half performance was the deciding factor of the match.

Only last week, the men from Galway pushed reigning league champions Munster all the way before going down 20-16.

And they continued that decent form in Wales before half-time as the Dragons, even with their Welsh Grand Slam-winning heroes of Toby Faletau, Luke Charteris and Man of the Series Dan Lydiate back in tow, struggled to get any possession.

Vainikolo crossed in both halves, with stand-off Miah Nikora booting 17 points against a Faletau try and kicks from outside half Lewis Robing and replacement Adam Hughes.

However, the home side were left frustrated in the opening half by some puzzling decisions from referee Giuseppe Vivarini that left the crowd furious.

Robling put the Dragons in front when Connacht were accused of a punch which referee Vivarini did not think warranted a yellow card. However, from there, it was all Connacht until the interval.

Big Tongan wing Vainikolo grabbed the first of his tries when he was put away by centre Kyle Tonetti on the left wing. The 27-year-old had 35 metres to race but just got there before the home defence dumped him into touch.

Nikora then made the Dragons pay for their mistakes. The New Zealander landed four penalties as the Welsh region were unable to get any reasonable possession.

Robling added a second penalty during Nikora's run of success and the crowd, feeling the ref was not on their side, let out a huge cheer that lasted for a good 20 seconds when he awarded them a scrum near the halfway line. Vivarini saw the funny side of it.

It turned to fury again, though, when Lydiate was sent to the sin-bin for illegality on the ground at a ruck, and Connacht, with flanker Mick Kearney at the fore, threw down the gauntlet.

The Irishmen pounded the Dragons' line and nearly got a second try when a cross-kick was taken on the right by wing Tiernan O'Halloran to feed Tonetti inside. However, the try was ruled out because O'Halloran had put a foot in touch.

Robling reduced the home arrears with his third penalty just before the break but Connacht landed a sucker-punch within seconds of the re-start when Vainikolo stretched his legs on the left and crossed from 30 metres.

It put Connacht well clear at 24-9, and gave the Dragons a mountain to climb if they were to add a second win to the encouraging victory over Edinburgh at Murrayfield seven days earlier.

Robling and Nikora shared further penalties as the home side eventually woke up and forced Connacht into periods of defence in their own half.

There was plenty of Dragons endeavour but little result as the visitors' cause was not helped when prop Ronan Loughney was yellow-carded for deliberate offside at an attacking home ruck.

For most of those 10 minutes that Connacht were a man short, it seemed only a matter of time before the Welshman scored.

However, they had to wait until virtually the ninth minute of Loughney's enforced absence before Faletau barged his way over in front of visiting lock Mike Swift.

However, it was too little, too late for the Welshmen as the Irish region, who finished the match with 14 men after replacement Eoghan Grace became the third sin-bin of the night for not releasing at a ruck, took only their fifth win from 19 league games and left the Dragons wondering what went wrong.