Two of basketball's greatest players, and likely Olympic team mates, will duel in the NBA Finals when LeBron James's Miami Heat and Kevin Durant's Oklahoma City Thunder clash in the title series starting on Tuesday.

James and his Miami cohorts are returning to the National Basketball Association (NBA) Finals determined to deliver on their celebrated promise two years ago to produce a passel of titles after the "Big Three" of James, Dwyane Wade and Chris Bosh joined forces in South Beach as free agents.

The young Thunder, eager to prove their future is now, make noise with a "Big Three" of their own as Russell Westbrook and James Harden provide plenty of firepower to augment the dynamism of Durant, who at age 23 has won three NBA scoring titles.

Talent abounds on these conference champions. Miami also takes advantage of the three-point shooting and defense of Shane Battier, and Oklahoma City relies on the shotblocking prowess of center Serge Ibaka.

But the spotlight shines on James and Durant, the NBA's best small forwards.

Durant, with his silky moves and sharpshooting long-range jumpers, averaged a league-leading 28 points in the regular season and 27.8 points in the playoffs.

James, the best all-around player in the world, scored at a 27.1 clip during the season and has poured in an average of 30.8 points a game in the postseason.

Oklahoma City built their team through the draft, with Westbrook, 23, and NBA Sixth Man of the Year Harden, 22, maturing on court together with Durant to form an offensive juggernaut that averaged 103.1 points a game during the season, nearly five points a game more than Miami.

All six of the key players are among the 18 finalists for the 12-man U.S. Olympic team defending the gold at the London Games, but for now it will be a no-holds-barred battle beginning in Oklahoma City for the first two games.

After beating an experienced though aging Boston Celtics team, the Heat face an entirely different challenge in the energetic Thunder, who showed they are coming of age after an about face against the championship-proven San Antonio Spurs.

San Antonio, who had won four NBA titles, took the first two games of their Western Conference series to run their win streak to 20 games before Durant and company swept four games in a row to earn a crack at the franchise's first NBA crown since 1979 in their former incarnation as the Seattle SuperSonics.

The Miami Heat fell short last year, losing in six games to the Dallas Mavericks, but they are back with a vengeance as James showed with a sensational series-saving performance in Game Six of the Eastern Conference finals against Boston.

James scored 45 points with 15 rebounds and five assists to carry the Heat on his muscular shoulders in the 98-79 road win in Boston before a collaborative effort from Miami's "Big Three" produced all 28 fourth quarter points for the Heat in Saturday's Game Seven win for a berth in the finals.

A key for Miami was the return of power forward Bosh, who played sparingly in the previous two games of the series after being sidelined due to an abdominal strain.

Bosh scored 19 points in the Game Seven triumph including a career-high three 3-pointers to open up the floor for the backboard jarring slams by James.

The series should also bring some well-deserved recognition to the head coach of the victorious team.

Heat coach Erik Spoelstra and Thunder pilot Scott Brooks have toiled in the background, but may play a pivotal role in the chess match of how best to use their high-profile players in what promises to be a scintillating best-of-seven showdown.

(Reporting By Larry Fine in New York; Editing by Frank Pingue)