Leeds United backed up their stunning win over Liverpool last week when they stormed back from 3-1 down at home to Bournemouth to win 4-3 with Crysencio Summerville again the hero with the winning goal.
Haaland had missed City's last two games with an injury and was deemed fit enough only for the bench against Fulham.
He was sent into the fray just past the hour mark with City, despite being a man light, pushing for the winner.
Almost immediately he had a headed goal ruled out for offside after a VAR check, but neither he, nor City, would be denied.
Pascal Gross's fifth goal of the season then secured the win for Brighton to move them to sixth with 21 points.