Lloyd James handed Orient a 1-0 lead on the stroke of half-time, only for Bradford to equalise in the 90th minute.
Nakhi Wells plundered a point for the hosts to stop Orient opening a three-point gap at the top of the league.
Patrick Bamford's 14th goal of the season and a 50th-minute goal for Ben Reeves condemned Wolves to 2-0 Molineux defeat.
Brentford moved into third place with a 1-0 home victory over Oldham, courtesy of a 90th-minute header from Jonathan Douglas.
Preston's 2-2 draw at Crawley allowed Brentford to leapfrog them in the table.
Paul Huntington and Josh Brownhill handed the visitors a 2-0 lead after just 16 minutes, and so the score stayed past the hour mark.
But Crawley hit back, first through defender Joe Walsh before striker Gary Alexander produced a last-gasp equaliser.
Britt Assombalonga took his Peterborough goals tally to 16 for the season with a brace at Gillingham.
His first stole an early lead before his second salvaged a 2-2 draw in the final minute.
Joe Martin and Cody McDonald had snatched the lead for the hosts before Assombalonga rescued his side.
Nouha Dicko and Ben Pringle fired Rotherham into a 2-0 lead at Bristol City inside half an hour.
Bobby Reid hit back for the hosts with less than 10 minutes to play, but Rotherham held out for a 2-1 victory that moves them up to sixth.
Jose Baxter's 67th-minute goal claimed a 1-0 home victory for Sheffield United over Swindon which was enough to carry the Blades two places above the relegation zone.
Walsall edged to a 1-0 win at Shrewsbury thanks to Milan Lalkovich's 54th-minute strike.
Jordan Burrow's three-minute brace pushed Stevenage into a 2-1 half-time lead at Port Vale, after Jennison Myrie-Williams had scored from the spot for the hosts.
Stevenage were on course for victory until Michael Doughty's red card with 19 minutes to play.
Just as the visitors thought they could hold out for victory, Tom Pope claimed a point for Vale, with the clash ending 2-2.
Tom Hitchcock and Chuks Aneke ensured Crewe claimed a point in their away clash with Coventry City.
Franck Moussa and Callum Wilson, with a penalty, struck for Coventry but Aneke secured a 2-2 draw.
Tom Lawrence bagged two goals as Carlisle overwhelmed Tranmere 4-1 at Brunton Park.
David Amoo and James Berrett were the other scorers for the hosts, with Ryan Lowe hitting an 81st-minute consolation for Tranmere.
Notts County pulled off a priceless 4-0 victory at Colchester to boost their relegation battle.
Jack Grealish, Morgan Fox, Callum McGregor and Gary Liddle claimed the goals that took them level on points with drop-zone rivals Crewe and above Bristol City.