Chiefs quarterback Mahomes threw for three touchdowns and danced over for a superb individual score to seal a deserved victory in the AFC Championship game at a freezing Arrowhead Stadium.
The Chiefs -- who last week trailed 24-0 before routing the Houston Texans -- once again did it the hard way, coming back from double-digit deficits in the first half to clinch the win.
It is the first time the Chiefs have advanced to the Super Bowl since their victory over the Minnesota Vikings in 1970.
"I'm lucky to be a part of this team with all these guys - it makes my job a lot easier," said Mahomes, who finished with 294 passing yards and 23 completions.
The win came one year after the Chiefs suffered an agonising home overtime loss to the New England Patriots at the same stage of the playoffs.
"It's amazing, to be here to do it at Arrowhead, these people deserve it. We're not done yet," Mahomes added. "We're going to get it."
The Titans had arrived on the threshold of a place in the NFL's showpiece game after a giant-killing run through the playoffs which included wins over New England and the top-seeded Baltimore Ravens.
- 'King Henry' toppled -
But despite starting strongly the Titans ran out of ideas once the Chiefs defense successfully contained the rushing threat of powerhouse running back Derrick Henry.
The Titans dominated for long periods of the first half, with Henry rumbling into gear to give the visitors the lead.
Henry helped put the Titans 10-0 ahead in the first quarter after gathering a direct snap from four yards to charge into the end zone.
The Chiefs responded swiftly however and were rewarded for successfully converting a fourth down on their next drive to set up a score for Tyreek Hill, sweeping around to the left to make it 10-7.
The Titans then ate up valuable minutes on a long second quarter drive which ended with a faked rush before quarterback Ryan Tannehill found giant offensive tackle Dennis Kelly with a one-yard pass over the top that extended the lead to 17-7.
But the Chiefs hit back in the closing minutes of the first half with two touchdowns that showcased their priceless ability to score quickly.
First Mahomes led the team on a five-play 63-yard drive with the quarterback hitting Hill for a 20-yard completion and a touchdown.
Mahomes then produced a moment of magic near half-time, eluding two tacklers before scampering up the sideline and spinning out of a tackle to dive into the end zone for a superb 27-yard score to make it 21-17 at the break.
The Titans' defense remained on the back foot through the second half, with Damien Williams rushing over from close range to make it 28-17 early in the fourth quarter before Mahomes then uncorked a monster pass to Sammy Watkins for a 60-yard touchdown that took it to 35-17.
The Titans scored a touchdown through Anthony Firsker with a brisk 80-yard drive but it was too little too late.