Complex sentence: In 1962, he helped the Texans win the American Football League championship in the classic double-overtime victory over the defending champion Houston Oilers, at the time the longest, and still one of the best professional football championship games ever played.
Split into simpler sentences: In 1962, he helped the Texans win the American Football League championship in the classic double-overtime victory over the defending champion Houston Oilers. At the time it was the longest, and it is still one of the best professional football championship games ever played.