After trailing by as many as 11 points in the first quarter, the Tigers (6-3) held a 31-30 lead at halftime before opening up a 43-40 advantage at the end of the third period despite losing senior shooting guard Kevin Peterson to an ankle injury late in the stanza.
Marshall County would miss Peterson's veteran presence in the fourth quarter, as Riverdale (5-4) outscored MCHS 19-4 over the final eight minutes to claim the 12-point victory.
The Tigers shot 50 percent (18-of-36) through the first three periods, but hit just 2-of-16 field goal attempts in the pivotal fourth quarter to finish 20-of-52 from the floor overall, which included a 4-of-19 effort from three-point range.
Although Marshall County committed only 10 turnovers, the Warriors outrebounded the Tigers 30-24 and held a 9-6 edge on the offensive glass.
Aided by a 5-of-9 shooting performance in the fourth quarter, Riverdale shot 40 percent (19-of-48) from the field overall and knocked down 8-of-23 attempts from beyond the arc.
The Warriors also committed just 12 turnovers and knocked down 13-of-16 free throws, while Marshall County went to the charity stripe only four times, hitting three.
Sophomore point guard Chris Walker turned in a strong all around performance and led the Tigers with 19 points, nine rebounds, six assists, and three steals. Peterson followed Walker with 13 points, and Cameron Bowers tallied five points and five rebounds. Kasey Pleas and Aaron Hobbs chipped in four points apiece for MCHS as well, while Malek Sain had two points.
"I thought for three quarters Chris Walker was arguably the most dangerous player on the floor. He can do that against anybody and we expect him to do that," said Wilson.
Tomaz Gray hit four treys and paced three Riverdale players in double figures with 20 points. Center Logan Thigpen also notched 15 points for the Warriors, while Steven Wilson added 10 points.
The Warriors jumped out to a 9-4 lead midway through the first quarter, before Marshall County cut the deficit to 12-9 a minute later on a runner by Walker and a Peterson three.
Riverdale rattled off eight straight points to make it 20-9 late in the first quarter, but the Tigers outscored the Warriors 12-4 over the next 3:54 with the help of five points apiece from Peterson and Walker to narrow the gap to 24-21 midway through the second.
After Thigpen hit a turnaround jumper to push the Warriors' lead to 26-21, Marshall County closed the first half with a 10-4 spurt, highlighted by a pair of treys from Walker and Peterson, to seize a 31-30 advantage at the break.
In the third, the Tigers continued to frustrate Riverdale and outscored the Warriors 12-10 in the quarter behind five points apiece from Bowers and Walker to extend their lead to 43-40.
Things, however, started to come unraveled for Marshall County in the fourth, as Riverdale put together an 11-0 run to pull ahead 51-45 midway through the period.
Hobbs scored on a layup to trim the deficit to 51-45 with 3:10 left, but the Warriors outscored MCHS 8-2 the rest of the way thanks to six free throws and a Thigpen layup to salt away their 59-47 win.