
The next 5 challenges for the America's Cup were made by Thomas Lipton through the Royal Ulster Yacht Club in his yachts Shamrock to Shamrock V, all of which were unsuccessful, although he came closest in 1920 in a match that had been delayed by the outbreak of the First World War. When he was 2 races up in a best of 5 race series and needed only one more race to win, he proceeded to lose the next 3 races to Resolute. It was the first time a challenger had won a race since Ashbury's second challenge of 1871.
Following the death of Lipton, T. O. M. Sopwith challenged in 1934 and 1937 in Endeavour and Endeavour II. The New York Yacht Club narrowly avoided defeat when again the challenger had won the first 2 races in a best of 5 race series and lost the vital third race on the final beat by the superior handling of Rainbow's skipper, Harold Vanderbilt. The defeat so devastated Sopwith and his crew that they were unable to win any of the remaining 3 races. The third race became controversial after the New York Yacht Club refused to hear a protest because Endeavour had failed to hoist a protest flag at the time of the foul, as required by US rules but not British rules.
Racing for the America's Cup was interrupted by the outbreak of the second World War and was not resumed until 1958 after the Deed of Gift had been amended by the New York Courts to allow racing in smaller and more economical 12 Metre Class yachts. A British challenge from the Royal Yacht Squadron was easily defeated in 1958, as was the first Australian challenge in 1962. The last British challenge for the America's Cup was defeated in 1964, although it did participate, unsuccessfully, in later Challenger Selection Series.
In 1967, 1970, 1974, 1977 and 1980, various Australian yacht clubs unsuccessfully challenged for the America's Cup.
The history making challenge of Alan Bond representing the Royal Perth Yacht Club of Western Australia in Australia II was ultimately the first challenger to win the America's Cup in 1983 after defeating the Dennis Connor helmed Liberty in a 4-3 final race victory, using an innovative wing keel that was the cause of much controversy and which continues in some quarters to this day.
Royal Perth Yacht Club of Western Australia failed to defend the trophy in 1987 when Dennis Connor in Stars & Stripes representing the San Diego Yacht Club successfully defeated Kookaburra III, an event which saw New Zealand's first participation in the America's Cup, losing the Challenger Selection Final to Dennis Connor. Unknown at the time, this was to be the spectacular swan song of the 12 Metre Class in America's Cup racing.