Possible Clues:

• Important motorsport's boring round of competition
• Tournament game
• Influential work covers function of leg getting to end of series
• Inspiring work in groundbreaking encounter for half the remaining contestants
• F1 to cut major part of championship
• Penultimate round of a competition
• Poem brought into major match towards end of tournament?
• It's provided in influential and important match
• Families gathered round television at last for It's a Knockout
• Poem written by Kipling during important match