A record 123.4 million people tuned in to watch the Kansas City Chiefs beat the San Francisco 49ers in Sunday's Super Bowl -- with the added attraction of an Usher-headlined halftime show and the attention-stealing presence of Taylor Swift.

Chief's quarterback Patrick Mahomes found Mecole Hardman in the end zone deep into overtime to seal a dramatic 25-22 win in what was also the longest Super Bowl game in history.

The victory makes Kansas City the first team to win back-to-back Lombardi Trophies since the New England Patriots in 2003-2004, cementing the franchise's right to be regarded as the NFL's newest dynasty.

CBS parent company Paramount said in a statement that a total audience of 123.4 million across all platforms made it the "most-watched telecast in history" -- up seven percent from last year's game.

Paramount said 120 million people watched the NFL championship game on CBS alone, a record for a single US network.

The viewership total came in just behind that of the Apollo 11 mission's 1969 lunar landing, which was seen by up to 150 million in the United States across the country's three television networks at the time.

Sunday's Super Bowl viewership was boosted by a confluence of non-sporting star power, with Usher leading an all-star cast that included Ludacris, Alicia Keys and Jermaine Dupri for the halftime show.

Slow jam king Usher held his own as he captured the magic of his late-1990s, early-aughts fame with a 13-minute, career-spanning medley including hits like "Love In This Club" and "OMG."

But pop superstar Taylor Swift didn't sing a word and was still the night's most-watched fan as she cheered on her boyfriend, Chiefs tight end Travis Kelce, from a luxury box with a coterie of famous friends including the rapper Ice Spice.

Swift's relationship with charismatic star Kelce has been a boon to television ratings, her every move offering headline fodder.

The "You Belong With Me" and "Anti Hero" singer's attendance at Chief's games has attracted many of Swift's younger, largely female fans -- helping widen NFL viewership to a new demographic.

Beyonce was also in the stadium Sunday with her hip-hop mogul husband Jay-Z -- and announced a new album during a commercial she did with telecoms giant Verizon, in which she repeatedly tries to "break the internet."

While the Super Bowl broke TV records in the United States, it is dwarfed by global viewership numbers for events including World Cup soccer finals, opening ceremonies for the Olympic Games, and the 1981 royal wedding of Charles and Diana.

The most recent World Cup Final, in which Argentina beat France in a penalty shootout in 2022, is estimated by FIFA to have been watched by nearly 1.5 billion people worldwide, across hundreds of channels.