Two late goals from Mathieu Manset hauled Reading from the jaws of defeat to deny Millwall a first away win in Berkshire for over a decade.
You would have to go back in the history books to January 2001 when a Neil Harris hit a hat-trick set The Lions up for a 4-3 victory to find the last time they enjoyed the sweet taste of success here.
And on Saturday in the season's Championship opener, Kenny Jackett's men must have thought that their wretched record against The Royals was close to an end after goals from Darius Henderson (49mins) and John Marquis (61mins) put the visitors firmly in the driving seat entering the latter stages. But Reading sub Manset had other ideas, capitalising on some indecisive defensive play before eventually thumping home on 85 minutes to reduce the arrears, and then heading in an 88th-minute cross from Jimmy Kebe to level matters up and set up a grandstand finish.
"It's disappointing to be 2-0 up and not see the game through," said Jackett, "But Reading have plenty of firepower and we aspire to match that. They will be right up there at the end of the season again I'm sure."
It had all looked so good for Jackett's Lions, who proved more than a match for Brian McDermott's team.
Beaten Play-Off finalists Reading were quick out of the blocks and so nearly scored the quickest goal of the day when, with just 11 seconds on the clock, Noel Hunt sprinted through on goal only to be denied by a brilliant block from David Forde in the Millwall goal.
Kebe fired wide on three minutes as the home side piled forward in search of an early opening goal.
But Millwall showed that whatever their hosts could offer, they could match with Liam Trotter (4mins) and then a super Hamer Bouazza strike (7mins) both flashing inches wide of the target.
James Henry, fired up against his former club, was unlucky to see his deft ninth-minute cross sliced into the hands of home keeper Adam Federici by defender Bongani Khumalo, before The Lions produced their best attack of the game. Trotter's crossfield ball looked to be too far for Henderson, but the big man showed his pace and strength, picking up possession and whipping over a dangerous cross that Royals defender Alex Pearce headed clear under pressure from Marquis.
Henry curled over the resulting corner and Tamika Mkandawire flicked a header a yard wide from close in as The Lions threatened again.
Back came Reading with a spell of pressure that Millwall did well to handle before Henry went close for Millwall just before the break, picking up Mkandawire's hooked forward pass, outpacing Ian Harte but then driving well wide of the target.
However The Lions got the second-half off to a perfect start when former Royals duo Henry and Henderson combined to put Jackett's men 1-0 up; Henry the provider for Henderson who converted from close range.
Reading nearly equalised within seconds though, when Shane Long, for the first time, managed to work an opening and unleashed a stinging drive that smacked the woodwork.
But when Marquis rose to head home Trotter's cross for Millwall's second just past the hour mark it looked as though The Lions were edging towards an impressive victory.
Jackett's men continued to produce some really crisp attacking play, and created a couple of decent chances to put the result beyond doubt.
Hamer Bouazza intercepted a poor pass from Andy Griffin just inside the Reading half and slipped a neat pass to the tireless Marquis, whose fierce shot took a deflection, looped up and fell kindly into the hands of keeper Adam Federici.
Then Marquis picked up another raking pass from Trotter, but seemed so surprised that the linesman's flag stayed down when he looked offside, that he perhaps had a tad too much time to decide on how to finish, enabling Federici to spread himself and block the young striker's goalbound shot.
A third goal and it would have been game over for Reading, but with the firepower at manager McDermott's disposal, there was always a danger that a first goal back for the Royals would lead to a second - and that's exactly what happened.
Manset, a 68th-minute replacement for Hunt, was allowed too much space before hitting a thunderous 25-yarder on 85 minutes to hand Reading a lifeline.
And barely three minutes later the powerful Manset rose unopposed to head Kebe's cross past the reach of a despairing Forde for the equaliser.
In an incredible finale, both teams went for broke in a bid to secure a third killer goal, and it was Millwall who were left wondering what might have been as skipper Paul Robinson twice headed over from Scott Barron corners and then sub Chris Hackett's drilled delivery across the face of goal needed the slightest of touches, but Henderson just could not get his toe to the ball to convert.
In the dying seconds Barron forced a flying save from Federici, who kept out the sub's stinging effort at full stretch to deny Millwall an opening day success.
Reading: Federici, Griffin, Karacan (Robson-Kanu, 68mins), Pearce, Leigertwood, Long, Hunt (Manset, 68mins), McAnuff, Kebe, Harte, Khumalo. Subs not used: Gunnarsson, McCarthy, Obita.
Booking: Pearce (90+3mins)
Scorer: Manset (85, 88mins)
Millwall: Forde, Dunne, Craig, Trotter, Robinson, Ward, Mkandawire, Bouazza (Barron, 68mins), Henderson, Marquis (Abdou, 85mins), Henry (Hackett, 79mins). Subs not used: Mildenhall, Racon.
Bookings: Dunne (17mins), Henderson (43mins), Marquis (54mins), Barron (75mins)
Scorer: Henderson (49mins), Marquis (61mins)
Ref: A. Bates
Att: 18,531 (away 2,235)