Before the game, Blackburn manager Mark Hughes made one change to the side that drew 1-1 with Tottenham Hotspur on Thursday night - with Shabani Nonda coming in for the suspended Jason Roberts up front.
Royals boss Steve Coppell made four changes to the side that lost 2-0 to Watford last weekend, with Doyle and Shane Long forming a new-look attack, Gunnarsson preferred to Steve Sidwell in midfield and Ulises De La Cruz returning at right-back.
With a top-seven finish still in their sights, Reading made the better opening to the game. On four minutes, Nicky Shorey sliced a left-foot volley just inches wide of the goal and, 12 minutes later, the new England 'B' recruit fizzed a crisp low drive onto the inside of Brad Friedel's left-hand post.
Rovers responded well, with Nonda and Morten Gamst Pedersen both firing comfortably into the arms of keeper Marcus Hahnemann, before opening the scoring with their next attack.
On 21 minutes, Tugay did brilliantly to keep the ball in play on the far touchline, Pedersen supplied the whipped cross towards Nonda at the near post and, after a collision with Hahnemann, who was subsequently taken off, the ball broke loose for McCarthy to slot home his 24th and arguably easiest goal of an incredible campaign for the South African striker.
But a quarter-of-an-hour later the visitors pulled level. Nicky Hunt swung a deep corner in from the right and Seol stole in at the back post to head home.
Four minutes before the break, Christopher Samba almost headed Rovers back in front, and four minutes after it, Hunt dragged his shot wide after finding himself clean through on goal.
On 54 minutes, Bentley surged into the box and fired a crisp right-foot shot just across goal, but a minute later the young England star did restore Rovers' lead.
McCarthy played in man-of-the-match Stephen Warnock down the left, the former Liverpool man galloped past Michael Duberry into the box, before squaring for Pedersen, who side-footed the ball onto the post with the goal at his mercy, but Bentley was on hand to tap home the rebound.
Again the lead was short-lived, as just three minutes later the visitors levelled for the second time in the game. De La Cruz crossed from the right and Doyle rose unmarked to head past Friedel.
Less than 10 minutes later and Rovers took the lead for the third time in the game. Bentley played in Brett Emerton down the right, who supplied a pin-point cross for substitute Derbyshire to send a diving header into the roof of the net with his first touch.
But Reading refused to lie down and struck back yet again on 77 minutes. Leroy Lita smashed a free-kick against the Rovers wall and Gunnarsson fired home the rebound into the bottom right-hand corner of Friedel's net.
As both sides pushed for the winner, Ivar Ingimarsson and Samba both had goals disallowed in the closing stages, but a draw was ultimately a fair result.