Complex sentence: In 1953 they had defeated England 6--3, becoming the first non-UK team to beat them at Wembley Stadium, and had thrashed England 7-1 in Budapest just before the World Cup.
Split into simpler sentences: In 1953 they defeated England 6--3, becoming the first non-UK team to beat them at Wembley Stadium. Shortly after that England had received another humiliating defeat, losing 7--1 to Hungary in Budapest just before the World Cup.