The two players combined to score 51 of their team's points, with McCoughtry pouring in a season-high 28 while also bringing down 15 rebounds.
Kosice, despite the Christmas-break departure of Linda Fröhlich to Municipal Targoviste and injury problems, looked as good as ever in clinching second spot in the group, a finish that is likely to earn them a much more favorable tie in the Eighth-Finals Play-offs.
Dupree finished with 23 points and 11 rebounds while teammate Miljana Musovic scored 12 points, handed out six assists and corralled four rebounds.
Prague forced their opponents to turn the ball over 20 times, yet they didn't compete with them on the boards as Kosice out-rebounded the home side 46-32.
The hosts had a good start, opening up an early 15-7 lead with Sonja Kireta scoring six points.
Kosice fought hard and didn't allow Prague to build on the advantage.
Instead, the Slovakians began to make their move two minutes into the second quarter when they trailed 27-26.
Dupree and McCoughtry scored all of the points in a 14-0 spurt that put the visitors in front for good.
A Musovic three-pointer at the buzzer from half-court gave Kosice a 51-37 lead at the break and they kept the pressure on in the third, taking a 65-55 lead into the final quarter.
Kireta battled, with two free-throws by the Croatian center reducing the deficit to 67-59.
A Katerina Elhotova lay-up for Prague and five straight points by teammate Evina Maltsi, including a shot from long range, cut the deficit to 69-66.
Not long after and Dupree and McCoughtry caught fire again, scoring all of the points in a 13-0 run that gave Kosice an 87-71 lead and effectively put the result beyond doubt.
For Prague, Kireta finished with the 21 points while Lindsay Whalen contributed 15 and Maltsi 12.
Štefan Svitek, Good Angels Košice coach:
"From the start we had a clear aim for todays game: to succeed, to surprise the opponent, which is one of the top EuroLeague teams, mainly offensively. Our main weapon was our defensive game, we were good at getting back to defense and we did not let USK score easy baskets on the fastbreak. We had problem under the basket due to the height advantage of our opponent but finally we managed to eliminate this. Our team was ready to fight and I feel we wanted to win more."
Katarína Hricková, Good Angels Košice player:
"We jnew that our main aim is to executet the defense plan - inside space as well as the perimeter. We had worked on it since the beginning and it paid back. We showed a fighting team spirit and this is what decided the game."
Lubor Blažek, ZVVZ USK Prague coach:
"We were prepared for today's game, we knew what to expect and I feel we wanted to win as much as Košice did as we were hoping to keep the second position in the group. Additionally we were playing on home court today. Our team kept fighting all game long, at the point when we closed the gap to just four points an important breakdown occured- we had 3 turnovers in a row and that basically decided the game. We were not succesful at our perimeter shots and this brought the team out of balance, we lost our cohesion."
Sonja Kireta, ZVVZ USK Prague player:
"We couldn't find the right rhythm all game long. We failed in defense, we tried man-to-man as well as zone defense but nothing could help us gain the proper balance and defensive comfort. I felt we all worked hard but we were either one step faster or slower that we should have been... Plus, we lost the long rebounds these were all taken by Košice players."