- Saka and Bellingham were England's driving forces with dynamic displays that underlined their emergence as two of the game's brightest young stars
Doha. Despite being in no state to continue amid fears of a concussion, the bloodied Beiranvand played on before finally being substituted.
England eventually penned Iran deep inside their own half and Bellingham delivered in the 35th minute.
Sterling found Luke Shaw on the left flank and his cross was perfectly weighted for Bellingham, who looped a fine header into the far corner.
Playing for Birmingham in the Championship just two years ago, the Borussia Dortmund star's goal made him England's second youngest scorer at a World Cup behind Michael Owen.
Eight minutes later another of England's gifted prodigies doubled the lead.
Maguire headed down a corner and Arsenal forward Saka swivelled to lash a superb left-foot finish into the top corner.
Sterling put the result beyond doubt with his first goal at a World Cup in first-half stoppage time.
Bellingham fed Kane, whose pin-point cross was volleyed home by Sterling with the outside of his boot.
Saka made it four in the 62nd minute when he shuffled across the Iran area before stroking his shot past Hossein Hosseini.
Taremi fired into the roof of the net to reduce the deficit three minutes later.
Rashford's cool finish in the 71st minute, 49 seconds after he came on, was followed by Grealish's 90th-minute tap-in.
Taremi struck from the penalty spot with the last kick of the game after a shirt pull by John Stones, but the margin of victory reflected England's total dominance.