A STOPPAGE TIME own goal handed Reading a thoroughly deserved draw against WSL leaders Chelsea in front of over 1,000 fans at Adams Park.
Royals took the lead when Remi Allen became the first player to score a league goal against Chelsea all season.
But the visitors battled back after the restart with goals from Karen Carney and Eni Aluko completing the comeback.
And it looked like missed chances would prove costly for Reading with Fara Williams hitting the post before Lauren Bruton, Brooke Chaplen and Allen all squandered big second half opportunities.
But there was time for one late twist as a Jo Potter free-kick in stoppage time was headed into her own net by Chelsea defender Magdalena Eriksson to spark wild celebrations and earn a 2-2 draw.
Despite playing a Champions League match in midweek, Chelsea came flying out of the traps as they looked to preserve their perfect start to the league season.
The Blues came into the game having won all four WSL 1 games so far, scoring 19 times and conceding none.
And they would have been ahead inside the opening 10 minutes at Adams Park were it not for an in-form Mary Earps.
The Royals stopper had to be alert to get down low and prevent a Drew Spence shot across goal before a huge stop to thwart former Reading striker Fran Kirby, after she broke through one-on-one.
Gemma Davison then curled an effort over the crossbar before Reading grew into the contest with Fara Williams volleying wide.
Chelsea continued to probe, but Potter in central defence was having a wonderful game to keep the strike duo quiet while also setting up attacks from the back.
And after riding out the storm, Reading, who were 10/1 with the bookmakers to win before the match, took a shock lead.
A ball into the box caused chaos and eventually fell kindly for Allen to sweep in the first goal Chelsea had conceded in the league all season.
Kirby sought a quick equaliser, but her shot was blocked by Rachel Rowe before Reading launched a counter-attack in the closing moments of the half through the impressive
Rachel Furness, but Williams’ eventual shot deflected into the arms of Hedvig Lindahl.
The hosts began the second half well, going close to adding a second when a deep corner from Potter was met at the back post by Furness, but her header was tipped behind.
And minutes later, Chelsea had levelled.
The visitors were awarded a free-kick 20 yards from goal and England international Carney expertly lifted the ball over the wall and into the bottom corner.
But Royals came agonisingly close to retaking the lead almost immediately.
After a winning a free-kick themselves, Williams lined up an effort from around 25 yards and her shot crashed back off the face of the post with Lindahl stranded.
Chelsea were looking dangerous down the flanks, but the clearer chances were falling Reading’s way with Allen scuffing an effort before Lauren Bruton wasted a golden effort.
Chaplen’s cross was only half cleared by Lindahl, falling for Bruton deep inside the penalty area but she shanked her volley wide.
And Royals were dealt the sucker punch moments later when Chelsea went down the other end and took the lead when substitute Aluko swept in from the edge of the box.
Chambers quickly turned to her bench, bringing on striker Kirsty Linnett for the last 10 minutes, as well as Becky Jane.
And the home side certainly served up a grandstand finish with Chaplen and Allen both breaking through one-on-one, but Lindahl denied them on both occasions as Chelsea clung on.
But Reading refused to give in, rescuing a point deep into stoppage time when Potter’s free-kick was flicked into her own net by Blues defender Eriksson.
Reading are in action at Madejski Stadium on Wednesday night against London Bees.
READING: Earps; Rowe, Pearce (c) (van den Berg 88), Potter, Scott (Jane 81); Bartrip, Furness, Allen; Williams (Linnett 78), Bruton, Chaplen.
Subs not used: Moloney, Green.
Goals: Allen (35), Eriksson (OG) (90+2)
Yellow cards: Chaplen (44), Pearce (80)
CHELSEA: Lindahl; Bright, Flaherty, Eriksson; Thorisdottir (Dunn 45), Mjelde, Chapman (c), Davison (Blundell 76); Carney, Spence (Aluko 66), Kirby.
Subs not used: Spencer, Cuthbert, Bachmann, Ji.
Goals: Carney (56), Aluko (75)
Yellow cards: Thorisdottir (33), Eriksson (90+2)
Referee: Rebecca Welch