Burton overcame promotion rivals Wycombe Wanderers at home thanks to Adam McGurk's winner, meaning they are now 11 points clear of fourth place.
Shrewsbury are a point behind following their victory at Mansfield Town, Tyrone Barnett scoring the only goal at Field Mill.
Wycombe's defeat to Burton means they are seven points adrift of the leaders in third, but their pain was eased by fourth-placed Bury conceding two goals in the final 11 minutes to lose 2-1 at home to Morecambe.
Bury remain four points behind Wycombe having played one game fewer, while Southend United - who face Bury in that game in hand - moved to within five points of the third automatic promotion berth after their 1-0 win at Hartlepool United.
Hartlepool's loss means all of the bottom five tasted defeat.
Cheltenham Town went down 1-0 at home to Stevenage, as did Tranmere Rovers to Luton Town, while Carlisle United lost 3-1 at Accrington Stanley.
The race for the final two play-off spots looks set for an exciting finale, after Exeter City defeated Newport County 2-0 to bring themselves to within a point of the top seven, while eighth-placed Plymouth Argyle lost 2-1 at Portsmouth.
Elsewhere, Cambridge United won 1-0 at Northampton Town with Harrison Dunk's goal in the first minute, Jamie Cureton netted a hat-trick as Dagenham and Redbridge thumped Wimbledon 4-0 and Oxford United's game with York City ended goalless.
