Reading let a two-goal lead slip as Junior Hoilett’s brace was pegged back by an impressive late Derby County fightback.
The Canadian international marked his return from injury with a glorious strike to open the scoring in the 38th minute.
Hoilett then put the ball past Allsop from close range following a free-kick to double the score.
Colin Kazim-Richards got a late goal back for Derby following a blunder from Reading keeper Luke Southwood.
A nervy finish at the Select Car Leasing Stadium was then compounded when Curtis Davies debt a bullet header past Southwood in stoppage time to rescue a point for the Rams.
The draw means Reading stay in 21st place, just three points above the relegation zone.
Returning to action for the first time since December 11, the Royals made two changes from their away loss at West Brom.
They welcomed talisman John Swift back into the starting eleven, while Junior Hoilett was also selected to start and Jahmari Clarke and Felipe Araruna were named among the bench.
Josh Laurent was handed the captaincy for the first match of 2022 in the absence of Liam Moore.
The Rams came into the contest in hot form with three successive wins to their name while Reading’s fixtures were postponed but were without manager Wayne Rooney in the dugout due to illness.
It was a lively start from the hosts who looked fresh having not played for more than three weeks.
They looked to take advantage of Andy Carroll’s height and presence in the box with some deliveries into the area early on.
But it was the visitors who won the first corner of the game when Craig Forsyth’s cross was blocked behind by Tyrell Ashcroft. Royals goalkeeper Luke Southwod palmed the set-piece away from his goal area.
Chances were few and far between for both teams with the early high press and energy from Reading quickly dissipated which gave the visitors more time in possession.
The clearest cut chance of the half fell Reading’s way in the 18th minute.
John Swift picked out Carroll in the middle with a pinpoint delivery, and despite the aerial expertise of the forward who headed the ball into the ground, he was denied by a sublime stop from Ryan Allsop.
Tom Dele-Bashiru tried to latch onto the loose ball in the aftermath of Allsop’s vital stop but couldn’t convert from close range.
The game went through a quiet patch before Southwood had to turn a deflected effort from Luke Plange round his near post.
Derby couldn’t forge any opportunities despite forcing a succession of corners, with the Royals defence staying organised.
The match had to wait 38 minutes for the first goal, but it was one well worth waiting for.
On his return from injury, Junior Hoilett cut infield onto his right foot and lashed an unstoppable curling drive past Allsop that flew into the top right hand corner.
The Rams should have been level within five minutes of the opener when Plange found himself with a free header from a corner just eight yards out, but he failed to find the target with a disappointing effort that rose over the bar.
Carroll nearly caught out Derby keeper Allsop who hesitated too long on the ball, but was able to make a fortuitous recovery to spare his blushes just before the break.
There was a change required at the break by Reading which saw Felipe Araruna replace Ashcroft for his first appearance after 15 months out injured.
Araruna was required to perform his defensive duty early after coming on when he turned an inviting Derby cross behind for a corner.
The gloves of Southwood were required early after the restart when he reacted marvelously to get a palm to Tom Lawrence’s strike inside the box.
Just moments after Derby’s big chance, Reading punished their opponents and scored their second of the match.
A free-kick to the back post was knocked down by Tom Holmes to find Hoilett, he took a touch and squeezed the ball in at the near post through the legs of Allsop to double his and his team’s tally.
Veljko Paunovic turned to his bench in the 65th minute by sending on Femi Azeez who replaced Alen Halilovic.
Reading pushed to find a third and another darting run into the box by Carroll nearly ended with a headed goal from Araruna’s delivery but he glanced the ball just wide.
Josh Laurent looked to get the Royals firing on the break with a driving run at Derby, but he was upended by Curtis Davies who picked up a booking.
Scott Dann came across to make a crucial block to get his body in the way of Davies’ shot.
From the resulting corner, the Rams were given a glimmer of hope when they grabbed a goal in the 86th minute.
A deep cross into the box went through the gloves of Southwood and was finished from close range by Colin Kazim-Richards.
Reading had a chance to wrap up the game in the 90th minute with a purposeful run from Azeez that ended with a shot fired into the side netting.
Derby hit back again and were level in the 91st minute when Davies powered a header past Southwood into the right corner to claw back a point for Rooney’s men.
The Royals are in FA Cup action this weekend away at National League Kidderminster Harriers.
Reading: Southwood, Ashcroft, Dann, Holmes, Rahman, Laurent (c), Dele-Bashiru, Swift, Halilovic, Hoilett, Carroll
Subs: Rafael, Araruna, Stickland, Camara, Azeez, Clarke, Puscas
Derby: Allsop, Byrne, Forsyth, Jagielka, Jozwiak, Bird, Lawrence (c), Davies, Knight, Thompson, Plange
Subs: Roos, Stearman, Williams, Ebosele, Morrison, Baldock, Kazim-Richards
Goals: Hoilett 38’, 56’, Kazim-Richards 87’, Davies 90+1’