Winning 3-0 against their rivals Celtic – their first victory over them this season – was important for a variety of reasons. Firstly, it gives the whole club some positive energy and momentum going into the summer, that Ange Postecoglou’s team are not absolutely invincible. Secondly, it takes the pressure off manager Michael Beale, whose stock with the Ibrox faithful may have fallen had they lost a fourth Old Firm clash in a row on his watch. And finally, it allows the players who will survive Beale’s major overhaul of the squad to believe that they can compete with the best team in the country.

Out of the starting XI that faced Celtic, it is likely that all 11 players – Robby McCrorie, James Tavernier, Connor Goldson, John Souttar, Ridvan Yilmaz, Nicolas Raskin, John Lundstram, Ryan Jack, Todd Cantwell, Fashion Sakala and Rabbi Matondo – will be around beyond the summer. Jack is the only one out of contract and recent reports suggest he may be offered a one-year deal. While it is debatable whether that exact team could mount a long-term title challenge to Celtic, they at least proved they are up for the challenge. The backbone of next season’s campaign is in place, with Goldson, Tavernier, Raskin and Cantwell giving Beale a platform to build from.

Much has been written already about how the manager, who arrived at Ibrox in December, has maxed out this current group of players. They are in desperate need of reinforcements if they are to get close to the level Celtic set week in, week out. The champions were off-colour in Govan, perhaps understandable given they’ve accomplished their mission of winning the league. Defeat to Rangers means they can no longer set a record points total and it was clear when speaking to Postecoglou and some of the players that the defeat hurt, by what happened at Ibrox is but a minor blemish on an otherwise impressive report card.

Celtic manager Ange Postecoglou shakes the hand of his Rangers counterpart Michael Beale at full time.

Celtic suffered from the absence of some key players. Cameron Carter-Vickers is clearly the best centre-back in Scotland and he was missed. Yuki Kobayashi started his first Old Firm match and while he is a very accomplished player with the ball at his feet, he will be disappointed with the way he was too easily outmuscled for the second goal by Souttar. Both deputy full-backs were called upon and Alexandro Bernabei did little to suggest he can wrestle the left-back berth from Greg Taylor, who was an unused substitute. Anthony Ralston did better on the opposite flank but Alastair Johnston’s force down the right is the stronger. All these changes seemed to spook the only regular in that back-line, Carl Starfelt, who got in a right pickle for Sakala’s third and clinching goal, crashing into Callum McGregor and then miscontrolling the loose ball.

In truth, Celtic looked shaken from the moment Cantwell opened the scoring on four minutes, lashing home a rebound after Joe Hart parried John Lundstram’s fierce drive. Ibrox absolutely burst into rapture and the old stadium quickly became a cauldron boiling with fervour and desire. Celtic had a 20-minute spell in the first half when Rangers loosened their grip and the big turning point for the visitors was when Hyeongyu Oh – preferred to Kyogo Furuhashi in attack – hit the post with a clipped effort when through on goal with McCrorie. The South Korean had a difficult day up front and has some improvement to make if he is to concern Kyogo for the No 9 berth.

Singling the 22-year-old out would be unfair, though, because far more senior players let themselves down too. The midfield completely misfired. McGregor was unusually quiet, although Cantwell sat on him the whole game, and Reo Hatate and Matt O’Riley never got on top of their Rangers counterparts. The aforementioned Cantwell had a quite magnificent match, opening the scoring and being the creative force for most of Rangers’ good play. The ex-Norwich man is not afraid of the physical side of the game and his efforts were applauded heartily as he left the pitch late in the match. Rangers’ other January signing Raskin also impressed in midfield and word must go to McCrorie, who was flawless once again in goal and must be giving Beale food for though about whether he is capable of being No 1 next season.

Three further rounds of Premiership matches remain. For Celtic, it is about preparing for the Scottish Cup final on June 3 against Inverness Caledonian Thistle, the only meaningful match left in the calendar. Defeat the Championship club and the treble is theirs. Pity poor St Mirren, though, who head to Parkhead this Saturday. Captain McGregor said the team would “take their medicine” and no doubt annoyed by the biggest domestic defeat of the Postecoglou era and back at home for the first time since being crowned champions, the Paisley outfit should be braced for a telling reaction.

Alexandro Bernabei and other non-regular Celtic starters had a day to forget at Ibrox.

For Rangers, they can at least attack their final trio of matches with a bit more relish. Hibs await at Easter Road on Sunday, another chance for this group of players to show Beale they are able to play a part next term. As the departing Alfredo Morelos sat on the bench – teenager Zak Lovelace was brought on ahead of him for his debut – it is clear that Beale has no time for the past. Rangers will hope that the buoyancy at Ibrox created by this derby win can carry them into next season, when the matches against Celtic will matter a great deal more.

Rangers-Celtic final word: The magnificent Cantwell, Postecoglou's deputies show weakness, Morelos and Lovelace