Parsifal, if individual skill as a yachting team held sway in the last America's Cup, ETNZ would have won; they were far more polished and handled their boat far better than Oracle.
If the most skilled team always won, the US Olympic Hockey Team would never had beaten the Soviets in 1980. (33 years and this still blows me away - Sports Illustrated named it the #1 Sporting Moment of the 20th Century)
If the richest teams always won, the New York Yankees would have won more than one World Series since 2000 and the Dallas Cowboys (worth $500 million more than the 2nd richest team) would have won at least one Super Bowl since 1996.
In the 2012 baseball playoff, the Giants came back to win their division series after being down 2-0 in a best-of-five game series, then coming back again in League Championship series after being down 3-1 in a best-of seven game series, then went on to sweep in the World Series (so they won seven straight). (Two amazing comebacks followed by a sweep.)
In the 1960 World Series, the Yankees won three games: 16-3, 10-0, and 12-2; the Pirates won four: 6-4, 3-2, 5-2, and 10-9, and thus the World Series. In total, the Yankees outscored the Pirates a total of 55-27, out-hit them .338 - .256, and out-homered them 10-4. (All the numbers save the number of games won point to the Yankees thrashing the Pirates.)
And as of right now, with just a couple games left in the season, the Oakland A's ($65M payroll, 4th lowest of 32 teams) have the third-best record in the Major Leagues, behind only the Red Sox ($157M, 4th-highest) and the Cardinals ($116M, 11th). The team with the 3rd highest payroll - Philadelphia at $160M - is sitting at a 73-88 record. The Yankees with a $230M payroll, highest in baseball, have only the 8th best record in the American League and were long ago eliminated from the playoff. (In this case I just hate the Yankees, so I'm gloating!)
The list of unthinkable underdog triumphs goes on and on, which, of course, is why the games are played.
(And, yes, I was bored enough to go ahead and research this WAY overblown post. As long as the Cup uses catamarans I'll be protesting; I wanna see traditional single-hull sailboats!)