Ekat met early resistance from the Polish outfit and trailed 33-32 midway through the second quarter.
Agnieszka Bibrzycka then shifted the momentum to UMMC with a three-ball.
The shot ignite a 14-0 run that put UMMC in front to stay.
Having led 48-35 at the break, UMMC emerged from the changing rooms with a full head of steam.
Two minutes into the second half Sandrine Gruda scored to take her points haul to 18 and give UMMC a 56-36 advantage.
Gdynia clawed their way back and pulled to within 65-55 late in the third quarter when Monica Wright sank a pair of free-throws.
Cappie Pondexter, however, had an answer.
She triggered an 8-0 surge with a tip-in as UMMC took command for good.
UMMC improved to 6-1 with the win and pulled to within a point of Fenerbahce, who thrashed Gospic Croatia (0-7) on Wednesday.
Bibrzycka and Gruda each had 20 points and Crystal Langhorne 18 for UMMC.
Center Milka Bjelica had 17 points and seven rebounds for Lotos.
"It's not our target in Euroleague to reach play-offs. Such games are a good experience for our team, they help us to progress. Our goal for the current season is to enter Final Four in Polish League. It has become a tradition for our team to have problems with UMMC centers. Moreover, we got late to the Sport Palace, and this was not good for our concentration."
Malgorzata Misiuk, Lotos:
"First of all, congratulations to the UMMC on their win! We are a young team, trying to play better and better and the games of this kind are useful for us. We didn't cope well with the UMMC centers. It was much harder for us to play in Ekaterinburg, because there are a lot of fans, who helped the hosts."
Gundars Vetra, Head Coach of UMMC:
"It was the second match when the opponent was late. It's not easy to wait. While waiting players lose concentration. We made sixteen turnovers, it's too many for us, and we let the guest team to make easy points - we had no right to do it! After the halftime our tall played more aggressively and this was fruitful for us."
Sandrine Gruda, UMMC:
"It was not an easy match, especially the first half. And we made too many turnovers."