The Baltimore Orioles pulled off one of the biggest Major League Baseball upsets in the past 15 years Sunday.

The Orioles, who were listed as high as +420 underdogs at some U.S. sportsbooks, knocked off Justin Verlander and the Houston Astros 8-7.

The Washington Nationals beat the Minnesota Twins as +390 underdogs in 2007, according to sports betting database BetLabSports.com, which has data back to the 2005 season. The Miami Marlins topped Clayton Kershaw and the Los Angeles Dodgers as +320 underdogs last season.

The Astros, the consensus World Series favorites, were one of the largest single-game favorites ever. They closed as -460 favorites at Caesars Sportsbook but could be found as high as -550 favorites at Station Casinos' sportsbooks in Nevada.

Houston is the ninth favorite of -400 or greater since 2005 and only the second to lose, joining the 2007 Twins. The Dodgers were -485 favorites against the Atlanta Braves in 2016.

The high price on the Astros' money line scared away many bettors at Caesars, where 89% of the tickets and 97% of the money was on the underdog Orioles.

Station Casino sportsbook director Chuck Esposito told ESPN his shop took minimal straight bets on the Astros-Orioles game, but added that Houston was a popular pick on parlay bets. Bettors often bet big favorites like the Astros by parlaying them with other teams to reduce the price.

Trailing 7-5 heading into the bottom of the ninth inning, Baltimore rallied for three runs, capped by Rio Ruiz's two-run homer with two out to give the Orioles the victory and snap their five-game losing streak.