Top scorer Lee Kaberry struck his 17th goal of the campaign and Shaun West sealed a 2-1 win six minutes from time at Warblington School.
Burrfields, who had taken a half-time lead through Sam Lucas, have now been knocked off top spot by Portchester Rovers.
More importantly, Meon Milton Reserves - now the only unbeaten team in the MSL - remain four points behind them but with three games in hand.
Lucas opened the scoring with a free-kick, but Horndean were level a minute after the restart, Kaberry dispossessing a Burrfields defender and netting from the edge of the 18-yard box.
Kaberry turned provider late on, a perfect cross allowing West to smash home a volley from six yards out.
Other impressive Horndean performers were left back Toby Hallet and Izzy Matonga, who caused the Burrfields left-back problems.
It was Horndean’s fifth straight league win, albeit one of those came when Wickham Dynamos failed to raise a team before Christmas.
United started the season with Chris Cooper as manager, but due to work commitments he stepped aside to concentrate on coaching alongside Charlie Coombes. Secretary Lewis Charlton took over the management duties.
Charlton’s first game in charge was a 4-4 draw against Burrfields, who at the time possessed a 100 per record record, in mid-October.
‘If we're completely honest we felt we should have won,’ recalled Charlton. ‘We led by two goals twice in the game. Two fantastic strikes got them the draw.
‘Ever since that game we have just seen the group grow in confidence, and the last couple of months have seen the team push on.’
Burrfields boss Brian Kirby said: ‘We have struggled for numbers of late due to a variety of reasons, but the bottom line is we didn’t show enough quality to put the (Horndean) game to bed.
‘We started poorly in the second half and gifted our opponents an equaliser within 90 seconds of the resumption.
‘Horndean, to their credit, remained competitive and probably wanted it more than my lads.
‘There is still plenty for us to play for this season but players’ attitudes and commitment must change if we want to retain our league title.’