Champions were on ropes until Forrest's late intervention

While still on the pitch, Alfredo Morelos led his team’s pressing from the front, splitting Celtic’s centre-backs to cut off passes between them. Behind him, Scott Arfield man-marked or covered Scott Brown, while the wingers – Daniel Candeias and Ryan Kent – took up positions in the channels that meant they could potentially threaten or intercept passes from Celtic’s centre-backs to their full-backs; instantly close down the nearby full-back should he receive; block forward passes in the inside channels; or step up to apply pressure to the centre-backs should an opportunity to do so arise.

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This defensive approach worked wonders in the previous Old Firm game, but Celtic came much better prepared for it this time around. Perhaps the most important of Lennon’s selection decisions was the starting of Kristoffer Ajer, who came off the bench at Ibrox. The Norwegian’s presence was significant as he has averaged more dribbles and progressive runs this term than any of his central defensive colleagues, and his ability to retain possession under pressure or advance with the ball at feet came in handy on several occasions on Sunday.

Along with the selection of individuals tailored to deal with the aggressive press of Rangers, Lennon implemented a more direct style of possession for this game. From goal kicks, and often in open play, goalkeeper Scott Bain would opt for long passes out towards the touchlines, with Mikael Lustig on the right-hand side his primary target. By choosing not to play out from the back, Celtic completely avoided the threat of being forced into turnovers in their own defensive third.

This more direct approach continued further up the pitch, too. One of the key features of Rangers’ pressing is the behaviour of their full-backs, who tend to go man-to-man against opposition wingers when the ball is on their side. This is done to prevent said winger from having time and space to receive the ball and turn. However, Celtic exploited this tendency consistently by playing balls over the top into the space vacated by Rangers’ full-backs for Odsonne Edouard to run on to. These passes were a regular route of entry into the final third for the home side. And, even if their French lone striker couldn’t get on the end of the ball over the top, they at least turned the Rangers defence and took away their opportunity to press forward.

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While these changes helped Celtic to mitigate the threats Rangers’ pressing strategy posed, it also prevented the hosts from playing their own usual game. The fact they ended the game with just 59 per cent of possession – one of their lowest tallies this season – underlined the newfound respect they have for their rivals. This respect was also evident in the way Lennon set his side up to defend.

Without the ball, Celtic’s 4-3-3 became a rough 4-1-4-1. Edouard performed a role similar to that of Morelos for Rangers, splitting the centre-backs and pressing high. He was often joined by one of the central midfielders, Callum McGregor or Olivier Ntcham, who would step up to pressure the centre-back with the ball if Edouard was unable to. As they stepped up, McGregor and Ntcham would simultaneously block passes to their opposite man, be it Ross McCrorie or Ryan Jack, in the process.

This was assertive defensive play with a heavy focus on the opposite man, something Lennon utilised during his time as Hibernian manager. This focus was most apparent on the Celtic left, where winger Jonny Hayes dropped back to track James Tavernier rather than staying in his position within the shape. Positional interchanges and combinations between Tavernier and Candeias on the right are key aspects of Rangers’ attacking play, so going man-to-man against them prevented either player from getting free in advanced areas. In this way Celtic, to an extent, copied Kilmarnock, who successfully handed Rory McKenzie a similar man-to-man job against Tavernier at Ibrox prior to the international break.

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The dynamic of the match altered completely when Morelos was sent off just after the half-hour mark. Rangers, who were already one goal down thanks to a wonderful dribble and finish from Edouard on the counter, were now a man down, and faced a huge task simply competing with Celtic. Fortunately, they have become accustomed to defending with 10, and they actually grew into the game without their top scorer.

It’s worth noting at this point that Michael Beale, the man Gerrard chose as his first-team coach, released a blog in 2017 in which he specifically wrote about situations where a team is down a man and must defend 10 v 11. In it he discussed keeping two players up in a 4-3-2 shape without the ball – this is something Rangers did in their opening game of the season, when Morelos was sent off away at Aberdeen, and it’s something they used to great effect once again on Sunday.

Naturally, Celtic’s dominance of the ball and territory increased. Without their frontman, Rangers opted against closing down their opposition’s centre-backs and instead had Candeias and Kent block the centre before pressing wide or backwards. This increased central presence discouraged passes into central midfield from Ajer and Boyata, meaning Celtic possession was often forced wide.

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Lennon’s response to this was to substitute Hayes for a more gifted attacker in Sinclair, while giving both Lustig and Kieran Tierney more freedom to push on and take up high positions down their flanks. Celtic’s passing was generally side to side, gradually circulating from one wing to the other, with the aim possibly being to stretch and tire out Rangers’ midfield three, who were now being asked to shift laterally and cover the entire width of the field as Celtic’s wingers pinned back Tavernier and Andy Halliday.

However, the freedom Celtic’s full-backs gained rarely caused serious problems for the visitors. Generally, it led either to the occasional decent shot from range or crosses into congested areas that were easily headed away. Sometimes McGregor or Ntcham would run beyond the ball and drag McCrorie away from the centre, opening space for Edouard to drop into and receive a diagonal pass inside from Lustig or Tierney, though too often Celtic’s possession remained in front, or to the side, of Rangers’ low defensive block.

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In looking to close the game, Celtic left themselves exposed in defensive transition at times. Gerrard’s decision to leave Candeias and Kent up top paid dividends, with the latter scoring the equalising goal. The home fans became nervous, and the psychology of both teams seemed affected by the change in mood. Celtic misplaced passes unnecessarily and lost all cohesion, while Rangers countered ominously whenever possible. Tierney and Boyata suffered injuries, meaning Celtic were forced to play with 10, while Jack spurned a golden opportunity to put Rangers 2-1 up. They may have enjoyed more of the ball, but when it came to clean scoring chances Lennon’s side weren’t quite so dominant.

Forrest’s 85th-minute winner continued Celtic’s habit for winning games late on, something they have also done recently against Dundee, Hearts and Kilmarnock. This and Morelos’ indiscipline were the dominant post-match storylines. However, the subtler narrative is perhaps more exciting, at least as far as Scottish football is concerned: This term’s title race is all but over, but Rangers are closer to Celtic than they have been for many years.