Paolo Di Canio’s side were undone by a superb volley from youngster Nick Powell and a second-half finish from Ashley Westwood.
The leaders, who had won 12 from the previous 13 league games, hit the woodwork twice through Simon Ferry and Paul Benson but failed to pull one back.
Burton’s latest defeat extended their winless run to 14 matches and ultimately cost Peschisolido his job, the Canadian sacked in a crisis meeting immediately afterwards. Torquay scored through Danny Stevens, Lee Mansell, Rene Howe and Taiwo Atieno, while the hosts’ Justin Richards tapped in after a mix-up in the Gulls’ goal.
Southend continued their League Two promotion push with a 3-2 victory over struggling Hereford at Edgar Street. Neil Harris, Elliot Benyon and Ryan Hall were on target with Yoann Arquin and Nathan Elder replying for the hosts.
Shrewsbury suffered a surprise defeat at crisis club Plymouth Argyle, Paul Wotton’s first-half club enough for the hosts to move above Hereford to third bottom.
Fifth-placed Crawley won 3-2 at home to administration club Port Vale, coming from behind twice to win through a Gary Alexander brace. Sergio Torres was also on target for the hosts, with skipper Marc Richards and Louis Dodds scoring for Vale.
Goals either side of half-time by Scott Rendell and Asa Hall gave Oxford a vital 2-1 win over play-off rivals Rotherham. Lewis Grabban scored a late penalty for Rotherham but it proved just consolation.
Gillingham eased to their fifth win in six matches to strengthen their hold on a play-off berth and further dent Cheltenham's ambitions of achieving automatic promotion with a 3-0 win. Jordan Obita scored twice and Chris Whelpdale added a third.
Kevin Ellison and Jack Redshaw struck either side of the break to give Morecambe a 2-0 win at relegation-threatened Barnet, while Aldershot stay in mid-table after a 1-0 win over Bradford, who are 18th.
Accrington moved closer to the 50-point mark with a 2-1 home win over Northampton, who lie 19th and only four points above the drop zone, while Bristol Rovers moved above AFC Wimbledon with a 1-0 home win.
Dagenham and Redbridge managed a 2-0 win over fellow strugglers Macclesfield Town, but the Daggers still stay bottom.