The Celtic vs Rangers derby proved to be as exciting as ever on Sunday after a thrilling and dramatic 90 minutes at Celtic Park.

In a match most pundits expected Celtic to dominate, Rangers matched them every bit of the way to pick up a point that gives them much pride as they head into a managerial era.

It was as poor a Celtic performance as we've seen all season and a match that most fans of the Hoops will likely want to forget quickly. Given they are 33 points ahead of the Gers in the table, many of the home fans expected another big victory in the manner of the 5-1 scoreline earlier in the season.

Full credit to Rangers though, who rallied well in the second half after going behind, crescendoing to an equaliser in the closing minutes of the game.

And of course, it wouldn't be one of these derbies without a few dodgy refereeing decisions too.

These are the FIVE lessons we learned from Sunday's big match...

As caretaker managers go, Murty wasn't half bad

Graeme Murty has had an exceptionally difficult task over the last month or so. The departure of Mark Warburton was acrimonious and damaging and given he has no first team managerial experience, many supporters were fearing the worst of his short time in charge as caretaker boss.

He's done his coaching credentials no harm though, guiding the Gers through two Scottish Cup ties, a last-minute league win against St Johnstone and now this impressive draw at Celtic Park. There were a couple of defeats along the way but in truth, could have been on the cards under Warburton too.

What his future holds we don't quite know yet, presumably he'll take his position back as coach of Rangers' U20s side. What we do know is that Rangers supporters are grateful to him for stepping up and for giving them a fun day out at Celtic Park.

Stuart Armstrong deserves international starts

Stuart Armstrong's emergence into a vitally important Celtic player has been one of the stories of the season for Hoops fans and he showed again on Sunday just how integral he is to the Brendan Rodgers midfield.

A livewire throughout his 72 minutes or so on the pitch, he could have got a hat-trick had things gone his way. First he hit the post with a daisy cutter free-kick, then he got his wonderful goal and in the second half he tested every inch of Wes Foderingham with a lovely shot from distance.

With the Scotland squad due to be announced early this week, it's time he not only gets a call-up to Gordon Strachan's side but also a starting berth in their upcoming matches. If he can reproduce the form he's shown at club level for his country, then things would certainly be looking up for the Tartan Army.

At their worst, Celtic still unbeatable

Celtic put in one of their worst performances of the season and still came through it with their unbeaten recored unscathed. That says something about Brendan Rodgers' team. It's clear it's going to take something mighty special to put this side to sleep and as determined as Rangers were, they just didn't quite have the cutting edge to finish them off despite a number of chances falling their way.

There's perhaps a slight relief amongst the Celtic support that they played so poorly and still didn't lose. Performances like these happen sometimes in football and we doubt it's a sign of this team's waining ability.

What will be interesting is the response to this performance in the upcoming derby semi-final at Hampden and how that match plays out. That's where the real test will be for both sides.

Rangers have an impressive team spirit

You have to credit Rangers for the way they battled back into the match after conceding in the first half. In the previous two league matches against Celtic they've wilted badly after conceding and allowed the Hoops to dominate possession and territory when they get ahead.

This time they dug in and focused on their own game and slowly but surely found themselves coming into the game more.

By the time Stuart Armstrong went off they were starting to build the pressure and in the final 15 minutes of the match it looked inevitable that they would equalise.

The team spirit and unity was there for all to see and that bodes well for the incoming Pedro Caixinha.

Scottish referees continue to be rubbish

It's fair to say that to most neutrals watching the game that Bobby Madden had a pretty poor afternoon. Missing a blatant free-kick that led to a big Rangers chance and then failing to award a penalty right at the death, his performance became the big talking point after the match.

The standard of refereeing in Scotland has been poor all season, perhaps more so than other years. There appears to be a match every weekend where a referee is under severe scrutiny and while that can be the case in other leagues, it appears particularly pronounced in the Scottish Premiership.

Neither Brendan Rodgers nor Leigh Griffiths were particularly happen with the penalty call speaking after the match and the fall out from it all is likely to rumble on radio shows and fan forums over the next few days.