1960 was always close, as you would expect a race to be where there is no major ideological distinction between the candidates and no incumbent running. In the wake of Eisenhower's 8 years the parties were ideologically indistinguishable and at very nearly equal strength in a national election. The result reflected that. Debates were, as always, nearly irrelevant. They make great fodder for media mythmakers, but they don't have much impact on voters.
Remember that the Dems had to commit massive vote fraud in Cook Couny and in Texas to win in 1960. It was hardly a case of an attractive candidate sweeping to victory on the strength of his debating skill.
You can spend a lifetime hunting and you won't find an example of electoral victory resulting from prowess in debate. It just doesn't happen.