Midfielder Barry Nicholson, on target in Saturday's 1-1 draw with Championship leaders QPR, struck with a well-placed header in the 16th minute at the City Ground to put Forest on course for their first home defeat of the season.
On-loan Liverpool left-back Paul Konchesky equalised with his first Forest goal on 54 minutes and Chris Cohen netted in the closing stages to put the home side 2-1 ahead before Jones' late leveller.
Forest threatened first when Konchesky volleyed just wide from 18 yards, but Preston quickly established a foothold in proceedings and winger Keith Treacy drilled a 25-yard shot just wide.
Two minutes later, Forest's former Preston favourite Paul McKenna drilled over the crossbar from 12 yards and in the 14th minute David McGoldrick fired a fizzing strike over from 30 yards.
However, Preston steadied themselves and led in the 16th minute when Treacy crossed dangerously from the right flank and Nicholson directed a firm header into the bottom right-hand corner from 12 yards out.
North End immediately pushed for a second goal but Lee Camp produced a fine save from Jones' 20-yard shot.
Treacy, an influential presence for Preston in recent weeks, then hit a fierce 30-yard free-kick which drew a fine block from Deepdale old boy McKenna.
Forest should have drawn level on the half hour as Konchesky crossed dangerously from the left flank, but Paul Anderson volleyed wastefully wide from 12 yards.
The hosts began to up the tempo as the interval approached and in the 43rd minute they fashioned a clear opening.
Cohen delivered a teasing cross which midfielder Lewis McGugan met with a 12-yard shot which drew a fine save from on-loan Everton goalkeeper Iain Turner, who tipped the ball over.
Forest moved through the gears as the second half began and in the 54th minute Konchesky drilled home a left-foot shot from 12 yards.
McGugan then sought to put the hosts ahead but his 25-yard effort flew over the crossbar.
Shortly before the hour mark, Preston boss Brown replaced Paul Coutts and Eddie Johnson with Leon Clarke and Adam Barton.
Forest replaced Marcus Tudgay with Dele Adebola but genuine goalscoring opportunities remained scarce.
McGoldrick hit a shot from 25 yards that Turner saved before Treacy fired over from long range.
McKenna then volleyed over from 30 yards and Forest looked to have snatched a winner in the closing moments when Cohen fired home a right-footed shot from 35 yards.
However, Preston were not to be denied and Jones headed in a cross from Treacy in the sixth minute of stoppage time.