Lee-Lo was yellow carded for the incident in the 28th minute, when his shoulder made direct contact with the head of Russian captain Vasily Artemyev.
After the match he was cited along with hooker Motu Matu'u.
Referee Romain Poite and Television Match Official Graham Hughes erred on the side of caution after deciding Artemyev had "dipped" his head going into the tackle.
An independent judicial committee ruled last night that while the fullback did alter his height it was not enough to justify reducing the punishment from a red card.
The committee said the tackle "was reckless, rather than deliberate" and carried "a high degree of danger".
The punishment was halved from six weeks because of Lee-Lo's "disciplinary record, good character and conduct at the hearing".
Lee-Lo will miss Samoa's remaining pool games against Scotland, Japan and Ireland but will be available for selection if the Manu make it to the quarter finals.
He has 48 hours to appeal the decision.
The decision comes 24 hours after Australian winger Reece Hodge was also handed a three-game suspension for a dangerous tackle of Fiji flanker Peceli Yato.
Motu Matu'u was also cited for a dangerous tackle on the Russian captain just two minutes after Lee-Lo had been sent to the sin bin.
The veteran hooker received the same punishment on the field but the committee has reserved its judgement for up to 24 hours, with a decision to be announced later today.