Everyone knows that Laver won the amateur Grand Slam in 1962 and the Open-Era Grand Slam in 1969. His intervening pro years are worth recollecting, also.
Laver turned professional after completing the Grand Slam in 1962. He quickly established himself among the leading professional players such as Pancho Gonzales and Ken Rosewall. During the next seven years, Laver won the U.S. Pro Championships five times, including four in a row beginning in 1966. In the first half of 1963, Laver was beaten badly by both Rosewall and Hoad. Hoad won the first 8 matches against Laver, and Rosewall won 11 out of 13. By the end of the year, however, with six tournament titles, Laver had become the No. 2 professional player behind Rosewall.
In 1964, Laver and Rosewall both won seven important titles (plus four minor events), but Laver won 15 of 19 matches against Rosewall and captured the two most prestigious titles, the U.S. Pro Championships over Gonzales and the Wembley Pro Championship over Rosewall. In tennis week, Raymond Lee has described the Wembley match, where Laver came from 5-3 down in the fifth set to win 8-6, as possibly their best ever and one that changed tennis history. Lee regards this win as the one that began and established Laver's long reign as world number one. The other prestige title, the French pro, was won by Rosewall.
In 1965, Laver was clearly the No. 1 professional player, winning 17 titles and 13 of 18 matches against Rosewall. In ten finals, Laver won eight against the still dangerous Gonzales.
In 1966, Laver won 16 events, including the U.S. Pro Championships, the Wembly Pro Championship, and eight other important tournaments.
In 1967, Rocket won 19 titles, including the three tournaments that unofficially constituted the "Professional Grand Slam" (the London Indoor Professional Championship at Wembley, US Professional Championships, and the French Professional Championships), plus the trial-basis Wimbledon World Professional Championship. That tournament held on Wimbledon's fabled Centre Court was the only professional event ever staged on that court before the open era began. In the final Laver beat Rosewall 6–2, 6–2, 12–10.