Barnsley strengthened their hold on second place in League One with a 2-0 home victory over Accrington Stanley - but Luton and Sunderland both dropped points away from home
Goals by Dimitri Cavare (41 minutes) and Mamadou Thiam (45) secured another three points for the Tykes - meaning Pompey kicked off at The Valley eight points behind them.
The win means Barnsley are now just three points behind leaders Luton, who were held to a goalless draw at Plymouth.
Sunderland looked to be heading for defeat at Wycombe, who led 1-0 through a first-half Alex Samuel strike, until Duncan Watmore got them out of jail with a 90th-minute equaliser. That put the Black Cats four points ahead of Pompey ahead of the evening kick-off at The Valley.
Three players were sent off at Adams Park - ex-Pompey midfielder Marcus Bean saw red for Wycombe along with Nathan Tyson; George Honeyman for Sunderland. Tuesday night sees Sunderland visit Barnsley.
Doncaster's play-off hopes suffered a setback with a 2-0 loss at AFC Wimbledon, who won with second-half goals by Steve Seddon and Shane McLoughlin. Peterborough were another play-off chasing side to lose - they had only Marcus Maddison's late penalty to show for their efforts at Bradford, where they lost 3-1.
A late Brandon Hanlan goal at Priestfield was enough to earn the points for Gillingham, beating relegation-threatened Oxford 1-0. Rochdale showed they have plenty of fight left in them near the bottom as they beat Shrewsbury 2-1 with goals from Kgosi Ntlhe and Jim McNulty.
Bristol Rovers are out of the bottom four after a 1-0 win at Scunthorpe, who visit Fratton Park next Saturday. Walsall, who host Pompey on Tuesday night, won 2-0 at home to Fleetwood, with Morgan Ferrier and Dan Scarr on target.
Last but not least it was a day of celebration at Bloomfield Road as Blackpool fans returned in their thousands following the ousting of the Oystons - they had a late own goal to thank for securing a 2-2 draw with Southend.