Pavel Pogrebnyak's late backheel saw Reading come out 3-2 on top in an enthralling third-round Capital One Cup tie at QPR in which they twice had to come from behind.
QPR got off to a great start when Junior Hoilett scored a superb solo effort 14 minutes in, although Kaspars Gorkss levelled things up against his former club minutes later.
The 1967 League Cup winners regained the lead when Djibril Cisse fired home from distance, but Nicky Shorey's superb 25-yard free-kick saw Reading draw level and provided a platform for them to snatch victory as Pogrebnyak backheeled home nine minutes from time. The former Fulham striker then saw a stoppage-time penalty saved.
Hoilett started brightly and he opened the scoring in the 14th minute, jinking past several defenders before sending a fine left-footed strike past Alex McCarthy. It was a well-deserved lead for QPR but one that barely lasted less two minutes as Gorkss rose highest to head home a Shorey free-kick.
Cisse forced McCarthy into action with a goalbound header from an Alejandro Faurlin free-kick, before Jamie Mackie wriggled free and fired across the face of goal. Reading, though, were now enjoying more possession and Clint Hill had to react quickly to prevent Pogrebnyak directing home an excellent Shaun Cummings cross.
Hal Robson-Kanu was the next to be denied by a block and, after Cisse shot harmlessly wide at the other end, Jimmy Kebe attempted to give Reading the lead in first-half stoppage time but saw his strike blocked by Hill.
Reading thought they had gone ahead when Pogrebnyak converted from close range, only for the goal to be ruled out. Cisse, redundant for the majority of the game, showed a flash of brilliance in the 71st minute when he put QPR 2-1 up with an unstoppable strike from distance.
Yet again, though, Reading struck back almost immediately and, after a Noel Hunt strike was blocked by Onuoha, a sweetly-struck Shorey free-kick flew in from 25 yards via the underside of the bar.
Then Pogrebnyak backheeled home from close range five minutes later to put the Royals in front for the first time. Pogrebnyak earned a stoppage-time penalty when he was adjudged to have been wrestled to the floor by Mbia, but Cesar saved the Russian's penalty low down to his left.