Tentoglou, competing in the long jump, achieved a new personal record and won first place by jumping at 7.99 meters.
The 20-year-old athlete was amazingly consistent throughout his attempts, with his first jump measured at 7.85 meters, the second at 7.99, the fifth at 7.96 and the sixth at 7.98 meters. The third and fourth attempts did not count.
Tentoglou managed to secure a spot in the indoor European Championships, which will take place in Glasgow in March.
Karalis won a gold medal competing in the pole vault.
The Greek athlete secured his participation in the next outdoor U-23 European Championships taking place in Gävle, Sweden in July with a vault measuring 5.55 meters.
The 19-year-old athlete started his career taking third place at the World Youth Championships in Colombia, in 2015.