The Blue Rocks had a field day at the plate, keyed by two of the Royals' top 25 prospects.
Tenth-ranked Emmanuel Rivera posted four hits, four RBIs and two runs while No. 25 Chase Vallot went yard twice and plated four in Class A Advanced Wilmington's 12-7 victory over Potomac at G. Richard Pfitzner Stadium.
Gameday box score
The four-hit night was the fifth of Rivera's career and the fourth time he drove in four runs. The 21-year-old came into Wednesday's contest batting .284 with multi-hit games in four of his last five games.
"Rivera has been consistent," Blue Rocks hitting coach Abraham Nunez said. "He has a good approach at the plate. It's just been a matter of time for him. He's such a good, young hitter. His bat is steady and he's been really good at the plate. It's just a matter of working on driving the ball to all parts of the field. His approach is outstanding."
The 2015 19th-round pick led off the second inning with a line-drive single to center field, then roped a two-RBI double to left in the third. He drove in another run with a knock to center in the fourth and added another run-scoring single in the seventh.
"He was trying to get a guy over to second base, but he got a fastball down and away and could drive it over the middle," Nunez said of Rivera's first RBI of the night. "That's just the kind of hitter he is. He takes what they give him, he has really good hand-eye coordination."
Batting .104 with three homers coming into the contest, Vallot has been trying to get into more of that kind of groove with Wilmington.
"He's had it a little bit tough to start the season," Nunez said. "We've worked on things in the cages, and tonight worked out good for him. He put two good swings on the ball and hit two home runs."
The 2014 conditional-round selection opened the scoring with a leadoff shot to left in the third and later added to the Blue Rocks' advantage with a three-run blast to left in the seventh.
"He got two strikes on him, but was still able to get a fastball and drive it out," Nunez said of the first long ball. "His next at-bat, he had a slider outside the strike zone but he could still drive it."
In 89 games with Wilmington a year ago, Vallot batted .231 with 12 home runs. The season before, he slugged a career-high 15 blasts between Class A Lexington and the Rookie-level Arizona League.
Since then, the organization has been watching for his power to evolve.
"We're just working on getting him to make contact," Nunez said. "We're working on that a lot in the cages. He's a guy who has power, and every time he makes contact, good things can happen for him."
Kansas City's top prospect Khalil Lee went 2-for-4 with two runs and an RBI while Brandon Downes doubled twice and scored a run.
Arnaldo Hernandez (3-0) allowed four runs on seven hits and four strikeouts over five innings for the win. Matthew Wynne struck out one in the final frame to pick up his second save.
Washington's No. 2 prospect Juan Soto, No. 28 overall, reached base five times for Potomac. He went 2-for-2 with two runs and three walks.