A goalkeeping error from David Stockdale led to Jordan Hugill giving Preston an early lead, before strikers Sam Baldock and Glenn Murray scored to put the Seagulls in charge of the Sky Bet Championship clash.
But towering Danish striker Makienok, on loan from Italian side Palermo, struck with his first league goal in the second minute of stoppage by heading in a cross from substitute Paul Gallagher from eight yards.
Unchanged Brighton threatened in only the seventh minute when winger Jamie Murphy fired over from the edge of the area following a pass by skipper Bruno.
The Seagulls gifted Preston the lead three minutes later when a poor back pass from Bruno put Stockdale under pressure and the goalkeeper's first touch let him down as he attempted the bring the ball under control.
The ball came off the former Fulham man's thigh into the path of striker Hugill, who stroked home his fourth goal in six league games from close range.
Brighton had an immediate opportunity to hit back, but central defender Lewis Dunk headed wastefully over from the centre of the goal after a pass by Oliver Norwood.
Albion had a lucky escape when midfielder Ben Pearson drove over in a good position after a corner from John Welsh.
Seagulls midfielder Steve Sidwell put a snap shot wide before Murray was off target for the hosts with a glancing header.
Preston came under pressure before the interval with Murphy putting a curling effort wide before having a close-range shot blocked.
Brighton's French winger Anthony Knockaert had a shot blocked by Chris Humphrey moments into the second half after a surging run by Murphy.
Murray, whose five goals have all been at home, shot into the side-netting from an acute angle a minute from the break.
Brighton equalised nine minutes after the interval through Baldock who scored for the second game running, pouncing from close in after Bruno delivered an excellent pass in behind the defence.
Murray then struck to give the hosts the lead after 65 minutes with a opportunist shot from just outside the six-yard box.
Murphy laid on the opportunity with a low pass and Murray got the better of Alex Baptiste before putting the ball under goalkeeper Chris Maxwell with his left foot.
Brighton looked on course to clinch their fifth win in the last six league games but Makienok, the 6ft 7in man called from the bench, had the final say by scoring in front of his own supporters to snatch his side a point.