Rangers earned a second Old Firm derby win in a week to cut the gap to Scottish Premiership leaders Celtic to two points and deepen the gloom at their city rivals.

With no away supporters in the ground, striker Ryan Naderi silenced Celtic Park before the break with his first goal in this fixture to stretch Rangers' winning run to six consecutive matches.

It also means Derek McInnes is the first Rangers manager to win his opening two derbies since Graeme Souness in 1986.

But his counterpart Martin O'Neill is left with questions to answer and solutions to find following a third damaging defeat in seven days.

Celtic had to chase this game for an hour after Naderi pounced from close range to covert once Kim Min-su's powerful effort was parried out by Viljami Sinisalo.

But for the width of the Finn's right-hand post, Rangers would have doubled their advantage almost immediately. Djeidi Gassama's clever chip came off the upright, keeping the game on a knife-edge.

Prior to going behind, Kieran Tierney - playing in a more advanced midfield role - skimmed the top of Ivor Pandur's bar and the Croat later superbly kept out Colby Donovan's header which seemed destined to equalise.

In front of a hugely frustrated home support, Celtic didn't seem to know how to break Rangers down and were relieved when a stunning shot into the top corner by Olwethu Makhanya was ruled out for hand-ball.

Celtic never really looked like extending their run of Premiership wins to seven and in the end went down rather meekly to their first league defeat since Dundee United beat them at Tannadice in March.

It's also their third consecutive defeat, after the League Cup loss at Ibrox last Sunday was followed by a Europa League reverse against Ferencvaros on Thursday.

They still top the table but there's likely to be some soul-searching in the three-week international break given the marked downturn in fortunes since their Champions League exit in Linz.

Rangers, by contrast, are riding the crest of a wave at the moment, back in contention at the top of the table and looking forward to a League Cup semi-final next month.

After two bad defeats, O'Neill started with five defenders, pushing Tierney further forward into midfield with Luke McCowan on the other side in what looked like a 4-4-1-1 formation, with Benjamin Nygren supporting lone striker Camilo Duran.

After Auston Trusty's early volley was deemed offside, it all went downhill for Celtic.

One down at half-time - and the width of a post from it being a two-goal deficit - the manager made yet more changes. Off came the largely-ineffective McCowan to be replaced by big-money summer signing Kasper Hogh.

When that change didn't have the desired effect, O'Neill went back to the wingers who'd been dropped: Haissem Hassan and Sebastian Tounekti.

Nothing really came off for them either, with Celtic completely devoid of the fluency and energy which propelled them to the title last season and saw them win their first six games of the current campaign.

There has been a real drop-off in form, quality and confidence and O'Neill will have a lot of thinking to do to figure out how to get the side back on track.

It all went exactly according to plan for McInnes. He knew - with no away fans in the ground - that his side needed to avoid conceding early.

Once that box had been ticked, his side settled well, got their noses in front and came within an inch of doubling their lead and sending Celtic Park into meltdown.

No Rangers manager since Souness in1986 had won his first two derbies. It's quite the feather in the cap, then, for McInnes, who not so long ago in Jablonec said he didn't recognise his side as they crashed out of Europe.

He very much does now. Six wins in a row for the concession of just a solitary goal. A real head of steam building up domestically without the extra demands of continental competition.

If they can build on this, Rangers could take some stopping given the momentum they're building up. Integrating new players is an altogether more comfortable experience when the side is winning.

A rocky start to the season is behind McInnes, who won't get carried away but will be able to enjoy his international break far more than he might have anticipated.

Rangers' recent good run in this fixture also continues. They've only lost one league derby in the last eight. If they can keep up that kind of run, they'll feel very confident about the season ahead.

Celtic manager Martin O'Neill: "We're still two points clear. We have a break coming up and it's a time to reflect, see where we are positioned and get on from there.

"I thought there wasn't much between the teams. Rangers scored, we had a couple of chances ourselves.

"The club has suffered defeat in the past; I've had that and it's a matter of fighting back and that's what you've got to try and do. Every defeat is really painful and it hurts every bit as much now as it did before.

"I have to reflect on things myself, see what I can do better to help the team. That's something that I'll genuinely think about.

"There are always big questions when you lose matches. You have to accept responsibility, which I do. Remember, this is my team. I am responsible for that."

Rangers manager Derek McInnes: "It's such an important win for us. To follow it up on the back of last week was really important.

"In the context of the season, it's just three points and it gets us three points closer to Celtic. We understood if we lost the game, that distance just starts to feel uncomfortable for us.

"It's still very early on. There's still 80-odd points to play for but I do think that winning here, particularly because we've got a young team, can only give them some much-needed confidence and belief on the back of last week.

"I like putting my name to this team at the minute and I think we've got a good thing going but we know how quickly that can change so we just try to keep those bad days to a minimum."