Leyton Orient have missed the chance to go top of League Two after they slumped to defeat against struggling Crawley Town.
The O's, who started the day one point behind leaders Plymouth Argyle, took an early lead in Sussex after Jay Simpson scored, but goals from Roarie Deacon and Mitch Hancox put the hosts ahead.
Alan Dunne was then sent off for the visitors, with Simon Walton scoring from the spot to condemn Orient to defeat, despite a late second from Simpson.
Instead, Portsmouth have edged ahead of Plymouth on goal difference after a second-half Matt Tubbs hat-trick helped them to a 2-1 win against 10-man Cambridge United.
Oxford United are also level with Argyle after George Baldrock scored 10 minutes from time to help the U's to a narrow win against AFC Wimbledon.
Mansfield Town are also within reach of top spot after two goals from Craig Westcarr and a third from Adi Yussuf saw them to a comfortable victory against relegation-threatened Newport County at Field Mill.
A brace from Shaun Miller saw Morecambe edge a five-goal thriller with Carlisle United at Brunton Park, while early goals from Marc Richards and Ryan Cresswell were enough for Northampton Town to beat Hartlepool United.
Yeovil Town came back from two goals down to draw 2-2 with Dagenham & Redbridge at Huish Park, but Barnet slumped to defeat at home to Accrington Stanley, with Sean McConville's strike earning the Lancashire club victory at The Hive.
Luton Town needed a second-half Cameron McGeehan penalty to earn them a draw against York City, who had led at Kenilworth Road through Keith Lowe's opener.
Results in full: Barnet 1-2 Accrington; Cambridge 1-3 Portsmouth; Carlisle 2-3 Morecambe; Crawley 3-2 Leyton Orient; Luton 1-1 York; Mansfield 3-0 Newport; Northampton 2-1 Hartlepool; Oxford Utd 1-0 AFC Wimbledon; Yeovil 2-2 Dag & Red