Webb's snappy try from a scrum was the difference between the sides at the break, the Ospreys leading 10-3 with Sam Davies and Jack Carty swapping penalties.

Carty's second successful kick reduced the arrears for Connacht to four points and Eoin McKeon's 57th-minute touchdown - converted by Carty - came while Ospreys number eight Ardron was in the sin bin.

However, the powerful Welsh side clinically saw out the result, stringing together 22 unanswered points to punish tiring Connacht and stay top of the PRO12 table.

The Ospreys were the early aggressors and Davies' fifth-minute penalty opened the scoring in Galway, while the erratic Carty missed a gilt-edged chance to respond.

James Connolly broke up a promising Ospreys spell by winning an important ruck penalty. Equally so, Niyi Adeolokun had to react sharply to tackle Olly Cracknell on a dangerous counter attack.

Connacht ended the first quarter on level terms, a Matt Healy surge down the left wing securing territory and Carty was successful with a subsequent penalty.

However, the home defence came under intense pressure as the Ospreys' share of possession rose to 72 per cent. And from a 29th-minute scrum, Ardron fed Webb who showed good strength to make it over despite the presence of Carty and Eoin Griffin. Davies converted for 10-3.

The Connacht pack exerted pressure nearing the interval and the Ospreys were fortunate to avoid sanction for clearly collapsing a maul just metres from their line. Adeolokun also threatened with ball in hand, but the visitors held out.

Carty punished a high tackle by Sam Davies with a 45th-minute penalty and Ardron's neck-high challenge on Finlay Bealham drew a yellow card six minutes later, following the input of TMO Alan Falzone.

A crooked lineout thwarted Connacht's initial attack but they bided their time, ramping up the pressure and then setting flanker McKeon free for a simple finish off a Bundee Aki pass.

Carty drew his left-sided conversion wide and it was his loose kick that was run back with interest by Dan Evans, the next scrum earning a penalty which Davies fired over for 13-11.

From then on there was only one team in it. The gaps that Glasgow Warriors ruthlessly exploited against the champions last week were evident again as Ardron muscled over from close range and then Webb ran the ideal support line to turn Ben John's brilliant break and offload into a try.

The bonus point arrived three minutes from time, industrious full-back Evans charging over halfway and sending Hassler over in the left corner, with Davies' final conversion completing his 12-point haul.