The NFL regular season is off to a crazy start and was capped by an impressive comeback upset by the Las Vegas Raiders over the Baltimore Ravens on Monday night. That Raiders win was one that made Week 1 a great one for spread underdogs -- a historically great one, in fact.

According to ESPN, 12 underdogs covered the spread in Week 1, which is the most in any opening week in the Super Bowl era. In addition, nine of those underdogs pulled off outright upsets, which is tied for any opening week in the Super Bowl era.

Here's how history was made:

According to ESPN, it marked the first time since 1983 that underdogs had a winning record (9-7) in Week 1.

The biggest upset proved to be the Steelers topping the Bills 23-16, according to ESPN. The Steelers were a 6.5-point underdog at most sportsbooks after losing five of their six games down the stretch to end the 2020 season.

That was the biggest point spread that was overcome in Week 1