Turns out, RSL is the latest victim.
Trevin Caesar gave Sacramento its first lead of the match in the 28th minute. A long cross from James Kiffie soared over players in the box, but Sacramento's Danny Barrera headed the ball across the face of goal before it went out. The ball squirted through traffic to an unmarked Caesar whose right-footed shot hit the back of the net.
RSL's Ricardo Velazco pulled RSL even in the 35th minute. Midfielder Omar Holness found Velazco streaking down the center of the field and the RSL forward took a touch around a Sacramento defender and buried a low, driven shot from 23-yards out to make it 1-1.
That momentum built by RSL was short-lived.
Barrera's second assist of the night found the head of Agustin Cazarez as Cazarez spun a header to the far post by RSL goalkeeper Lalo Fernandez, giving Sacramento a 2-1 lead in the 43rd minute.
Sacramento tacked on another a few minutes later.
Jeremy Hall converted on a penalty kick in the first minute of stoppage time in the first half to put Sacramento up 3-1. Sacramento piled it on again, adding its fourth goal of the night as Kiffie found Barrera to put the home team up 4-1 in the 71st minute.
Petke started eight first-teamers in Velazco, Holness, Fernandez, Jose Hernandez, Jordan Allen, Justin Schmidt, Reagan Dunk and Sebastian Saucedo. Fernandez made his RSL debut in goal, while Allen, who went 45 minutes, returned from a lengthy leg injury. Both Saucedo and Brooks Lennon, who came on for Allen, returned to action after starring at the U-20 World Cup with the U.S. national team.
RSL signed eight Monarchs players to short-term agreements to play in the Open Cup. Included were Wednesday's starters Nick Besler, Max Lachowecki, James Moberg, plus substitutes Connor Sparrow, Michael Gallagher, Kyle Curinga, Andrew Brody and Daniel Haber.
The magic run the Monarchs have been riding tying a USL record of eight straight wins didn't rub off on RSL in its Open Cup opener. Instead, it was an all-too-familiar result in a disappointing season.