KAMPALA, Sept 8 (Reuters) - Winger David Obua scored a hat-trick to lift Uganda on to the verge of African Nations Cup qualification as they beat Niger 3-1 in their Group Three encounter in Kampala on Saturday.Uganda now to have to wait until the completion of the qualifiers next month before they know whether they have earned one of the three berths reserved in the finals for the best runners-up in the qualifying group. The win pushed Uganda to 11 points and with a five goal positive goal difference. Nigeria have already secured qualification as group winners. Obua got Uganda off to a dream start with a second minute penalty but Niger, who were already out of contention, pulled a goal back on the stroke of half-time through Hassayedou Idrissa. Obua then restored the lead in the 76th minute and completed his hat trick 10 minutes later. The 12 group winners plus three best placed runners-up join hosts Ghana in the finals next January.