American Football: Sibling showdown as 49ers and Ravens head for the 'Harbaugh Bowl'

Brothers Jim and John will make history when they lead out respective teams at the Super Bowl

Super Bowl XLVII? They should rename it the Harbaugh Bowl. Exactly one year ago Jim and John Harbaugh, head coaches respectively of the San Francisco 49ers and Baltimore Ravens, fell at the penultimate hurdle. This time around, football's biggest game will truly be a fratricidal affair – the first time that a pair of brothers, separated in age by just 15 months, have ever been in charge of the opposing teams.

And the symmetry doesn't end there. The Harbaughs are not just the first brothers to be NFL head coaches. They both got to the Super Bowl the hard way, by winning their championship games on the road, to cap seasons in which they reshaped two teams celebrated for their defense into showcases for offense.

Sunday produced two gripping contests – but the real upset belonged to Baltimore's John. A year ago the Ravens trooped off the field in dejection after a 20-17 loss at the New England Patriots' Gillette Stadium, having botched a touchdown attempt and then missed a simple field goal in the dying seconds that would have tied the game.

For a while a repeat looked on the cards this time, as Tom Brady's heavily favoured Patriots staked out a 13-7 half-time lead, with statisticians noting that in the previous 67 games started by Brady, New England had never lost when they were ahead at the half. This time though there was a different script.

The quarterback who took command was Baltimore's Joe Flacco, while usually clinical Brady unravelled – as did his receivers. There were dropped passes, tipped passes and interceptions. Flacco by contrast was impeccable, finishing three straight drives with touchdown passes and propelling the Ravens to a 28-13 lead. Baltimore's defense did the rest.

Brady's sixth Super Bowl appearance, a seeming quasi-formality beforehand, was not to be, and long before the end Gillette Stadium was half-empty, as disbelieving fans streamed home. But Brady's failure is Ray Lewis's gain. Three weeks ago, the linebacker whose 17 years of unbroken service have made him the face of the Ravens' franchise announced this season would be his last. Now he has a chance to write a storybook ending to his career.

If the AFC Championship game produced a shock, the NFC one went by the formbook – though not before Jim Harbaugh's 49ers fell to an early 17-point deficit against the Atlanta Falcons. But then San Francisco demonstrated why most people viewed them as the NFC's strongest team – and why Colin Kaepernick is set to be one of the League's next generation of superstar quarterbacks.

After the 49ers had sliced 14 points off that lead with a couple of touchdowns, the Falcons responded with one of their own to lead 24-14. But Kaepernick reeled them in. Last week he destroyed Green Bay with a record 181 rushing yards. This time he threw 16 completions out of 21, for 233 yards in all. Brought in by Jim Harbaugh only in November, Kaepernick was making just his ninth start on Sunday. The 10th will be in New Orleans on 3 February on American football's biggest stage of all: the Harbaugh (sorry, Super) Bowl.