UEFA says its appeals committee ruled that Lazio need close only the Curva Nord section of the Stadio Olimpico when Apollon of Cyprus visits on Nov. 7.
Lazio was prosecuted for "racist behaviour" by fans and an offensive banner when it hosted Legia Warsaw on Sept. 19.
Fans "performed racist chants against the Slavic people," according to monitors at the match from anti-discrimination group Fare.
Lazio was repeatedly sanctioned by UEFA last season over its fans' behaviour, including making fascist salutes.
Lazio leads the four-team group after two matches.