William Shatner -- 'Peyton Manning's My Boy' ... Broncos WILL Win Super Bowl

Sorry KC fans, the Chiefs ain't got a Vulcan chance in hell of winning the AFC ... so says "Star Trek" god William Shatner, who tells TMZ Sports the Lombardi Trophy's got Peyton Manning's name written all over it.

Shatner and his family had just touched down at LAX last night (he's even got his vacation hat on) ... when he told us why he's supremely confident that Denver won't be stopped in the NFL Playoffs.

Turns out ... Captain Kirk and Captain Manning are "boys."