Atrás
This all-League One tie turned out to be one of the most one-sided of the day, with Posh boss Robbie Savage watching on in horror as his side were pulled apart.
Reading went ahead after 26 minutes as slick passing led to Andy Rinomhota playing in Daniel Kyerewaa, who found the bottom corner via a deflection.
The Royals doubled their lead in the 34th minute when a brilliant cross from left-back Haydon Roberts was met by a diving header from top scorer Jack Marriott.
It was effectively game over in first-half stoppage time as Savage deepened his father’s misery when he took possession after the ball ran off Marriott, with his deflected effort finding the top corner.
Jamie Reid added a fourth for the visitors in the 72nd minute when Paudie O’Connor nodded Savage’s free-kick into his path for him to lift over Peterborough goalkeeper Alex Bass.
Reading weren’t finished yet as they struck yet again four minutes later when Liam Fraser’s pass put Reid clean through to score his second.