#6 (Joint sixth) Manchester United (1998-99) - 29 matches
Manchester United secured a place for themselves in the history books in 1999 after they won the Premier League, FA Cup and the Champions League all in one season, to become the first and as of 2020, the only English team to complete the continental treble.
They became household names after their remarkable achievement, which was masterminded by Sir Alex Ferguson and executed brilliantly by The Class of 92. Though it is only natural to be awed by such incredible feats, we should not let them distract us from the fact that in the same period they went undefeated in the league for 29 games straight.
It all began after a series of disappointing results just before the winter break, in which they had drawn three games back to back, followed by a 2-3 defeat at home to Middlesborough. Since that shock defeat, they did not lose a single game and went on the lift their fifth Premier League title.
The 1999-2000 season also began on a similar note for the Red Devils, in which they managed to extend their undefeated streak to a total of 29 games.
Their unbeaten record came to a sudden end on 3 October 1999, when Chelsea produced a sensational performance at the Stamford Bridge to crush the reigning champions 5-0. Despite their run coming to an end, they managed to retain their title later that season.