Dumbarton 0 Rangers 1

Kris Boyd's third goal in five games handed Rangers a 1-0 win over Dumbarton and a place in the William Hill Scottish Cup fourth round.

The Ibrox frontman endured a frustrating start to the season as he failed to score in any of his team's first eight league games. But since breaking his Scottish Championship duck against Raith Rovers a fortnight ago, the former Scotland striker has gradually resdicovered his scoring touch.

The 31-year-old fired Rangers ahead seconds before the half-time whistle and just moments after another strike had been ruled out for offside. The Premiership record scorer's confidence is still not at maximum levels, however - a fact highlighted by an easy miss right at the start of the second half which would have made life a lot easier for Ally McCoist's side as they had to dig deep to see out the win.

Having gone 22 years without visiting the town of Dumbarton, Rangers were back beside the Rock for the second time in a week. McCoist's men were comfortable 3-0 victors over the Sons last Saturday as the sides met in the league.

But it was the hosts who created the first opening of the third-round tie as Mitch Megginson forced Gers' stand-in keeper Lee Robinson - replacing Steve Simonsen following his midweek collision with a post - into an early finger-tip save.

Dumbarton had been happy to have a go at their guests last week but having learned their lesson, boss Ian Murray set up a five-man defensive guard at the back to protect against both the threat from out wide and through the middle.

That left Rangers to toil through their usual disjointed motions, with their only attempt in the first half an hour a wild swing from Ian Black which flew both high and wide.

Ricky Foster came closer as he drove inside from his right-back slot to shoot but even then it was nowhere near to troubling Dumbarton keeper Jamie Ewings. Rangers lacked tempo, inventiveness and composure. They were just lucky the same could be said of their opponents.

But eventually their quality began to shine through. Boyd had the ball in the net four minutes before the break as he re- directed Foster's errant shot but saw it chalked off after wandering offside.

Thankfully for the Glasgow giants, the striker's next effort did count. Lewis Macleod's through ball found Boyd 15 yards out and after sorting his feet out, he clipped the ball off the base of the post and into the net.

His scoring touch remains fragile, though, and he made a complete mess of his next opening five minutes into the second period. There was nothing spectacular about Nicky Law's long punt but it caught out the Dumbarton defence as Boyd darted through on Ewings. He only had the keeper to beat but put his finish straight at the keeper's legs.

Macleod then fired into the side netting before seeing another effort saved easily by the keeper. Rangers remained in control but the longer they went without adding to their lead, the more Dumbarton believed they could grab something from the match.

The Sons thought their moment had come as Andy Graham got his head onto Scott Linton's long free-kick but Robinson proved again he was an able deputy in goal with another solid save.

Garry Fleming went close with a 20-yard strike 10 minutes before time as the away support held its breath. Substitute Jon Daly could have eased their fraying nerves but fired over from 10 yards out as Rangers eventually clung on for victory.