A second-half strike from Barry Ferguson put Rangers into the Scottish Cup quarter-finals at the expense of a Ross County side who had made a memorable recovery from going 2-0 down after just 17 minutes.

Tore Andre Flo had supplied both Rangers' goals, but journeyman forward Alex Bone repeated the trick for the home side either side of half-time.

Ferguson capitalised the only time the home defence showed their lower league status - but Dick Advocaat's side still needed a last-minute goalline clearance to prevent an embarrassing Ibrox replay.

County's neighbours Inverness Caledonian Thistle famously beat Celtic at Parkhead in the cup this time last year, and videos of that occasion are still a popular item on the Moray Firth.

In the end it needed the captain's goal to prevent County from being able to issue their own commemorative tape.

Flo's strikes in the fourth and 17th minutes appeared to have allayed whatever fears had travelled up the A9 with the Rangers fans, who gave their side a noisy backing.

Rookie centre-back Robert Malcolm supplied the pass for the opener - although it was Kenny Miller's turn, which bamboozled Brian Irvine in the County defence, that set up Flo for a cool finish into the bottom corner.

His second was similar in that it had come from the same side of the park and finished up in the same area of the net, with Neil McCann the supplier this time and Flo doing the turning himself - fooling Mark Perry, before slotting past goalkeeper Nicky Walker.

But County needed just three minutes to pull a goal back, with top scorer Bone needing latching on to a header into the Rangers' danger zone.

It took Rangers more than 10 minutes to regain their composure, and when they did Flo was denied a hat-trick inside 33 minutes by a fine Walker save.

Tugay played the ball forward for Miller with his back to goal and a defender in close proximity, and his lay-back to Flo on the edge of the area was perfect for a first-time shot.

It was advantage Rangers at the break. But the First Division side, who had lost 2-0 to the Ibrox men back in 1966 when they were a Highland League outfit, had shown signs that they might profit again.

Fernando Ricksen was in the Rangers line-up for the first time before a five-match ban comes into force, and County's skilful Frenchman Karim Boukkra was keen to test him.

One nutmeg through the Dutchman's legs ended with Ferguson wading in to upend him - and from the free-kick move Boukkra gave Ricksen the slip before firing wide.

The signs that Rangers were vulnerable were there, and that man Bone proved it with an equaliser within 10 minutes of the restart.

Irvine and Bert Konterman tussled in the box, and the home fans were calling for a penalty when their man went to ground.

Play went on, and Ricksen could not get the ball away any further than the former Stirling Albion man who slotted gleefully past Stefan Klos.

Klos was needed to stop Boukkra planting a screamer into the net from long range, tipping over at full stretch.

Then Ferguson had his say.

County failed to pick up his run into the box on to Claudio Reyna's ball through the centre of the defence.

The hosts then almost snatched an equaliser with a minute to go when Klos came and missed his punch - and it needed Scott Wilson to hack Irvine's header away before it crossed the line.

There was also still time for Miller to miss a sitter at the other end.

Teams:

Ross County: Walker, Perry, Maxwell, Irvine, Robertson, McCormick (Fraser 76), Steven Ferguson, Boukkra (Holmes 72), Henderson (David Mackay 64), Coyle, Bone.

Subs Not Used: Hamilton, Cunnington.

Booked: Perry, Steven Ferguson, Bone.

Goals: Bone 19, 53.

Rangers: Klos, Wilson, Konterman, Malcolm, Reyna, Tugay, Ferguson, Ricksen, McCann, Miller (Johnston 90), Flo.

Subs Not Used: Moore, Carson, Christiansen, McHale.

Goals: Flo 3, 16, Ferguson 62.

Att: 5,972

Ref: M McCurry (Scotland).