Hull KR scored three times in the first 13 minutes of the second half on their way to completing the double against engage Super League leaders St Helens.

Jake Webster grabbed the first and Daniel Fitzhenry pounced for two tries in quick succession to leave St Helens stunned.

The opening 40 minutes had been pulsating, with non-stop end-to-end action, as referee Steve Ganson let the match flow, but the 6-4 scoreline in the home side's favour at the break indicated there was little to choose between the teams.

St Helens made two or three uncharacteristic errors early on but Rovers showed traces of nerves too.

Jake Webster sustained a head injury after 14 minutes when he halted St Helens' Matt Gidley with a tremendous tackle, while James Roby and Leon Pryce kept the home side on the back foot with a couple of fine 40-20s.

Saints took a 21st-minute lead when Roby's short ball sent in James Graham, however Jamie Ellis was off target with the conversion.

As half-time approached Hull KR stepped up their performance and a mistake from Pryce after 39 minutes led to Kris Welham snapping up the ball and racing 35 metres to score, with Michael Dobson converting.

That meant the hosts were ahead narrowly at the break, and they began the second half in fine style, trapping Paul Wellens behind his own line for a drop out and from the play which followed Jake Webster went over in the corner for an unconverted try.

Three minutes later Ben Cockayne blasted his way down the middle before sending in Daniel Fitzhenry, with Dobson adding the extras.

Dobson had a score disallowed on 50 minutes when he knocked on, however Fitzhenry added to Saints' discomfort with his second try on 53 minutes, Dobson again converting.

Liam Colbon went over for Rovers on 61 minutes but his effort was chalked off for a forward pass.

With seven minutes to go Dobson was just off the mark with a drop-goal attempt.

Rovers' joy was complete when Peter Fox went over in the left corner with three minutes left and it hardly mattered that Dobson fluffed his conversion attempt.

Saints snatched a consolation try in the last minute when Ade Gardner went over in the corner for a try converted by Ellis.