Joe Root celebrates a century in his maiden Test as captain, England v South Africa, 1st Investec Test, Lord's, 1st day, July 6, 2017© Getty Images
Joe Root was struck on the helmet during his first-day century, England v South Africa, 1st Investec Test, Lord's, 1st day, July 6, 2017© Getty Images
Kagiso Rabada claimed the big wicket of Ben Stokes for 56, England v South Africa, 1st Investec Test, Lord's, 1st day, July 6, 2017© Getty Images