This research used the qualitative multiple case study and phenomenological designs to explore how, without training, university teachers in Ghana managed large student numbers in the virtual environment during COVID-19. The study examined further the challenges the teachers faced in their virtual instructional delivery. Twelve participants drawn purposively from four large Ghanaian universities participated in individual interviews and follow-up virtual class observations. The findings revealed that the participants employed two management techniques in their virtual teaching--regulating the behaviour of learners and controlling instructional content. The research further uncovered that, although the teachers' complaints generally centred on environmental constraints and inadequate institutional support, those whose difficulties included using virtual tools did not have virtual teaching experience before the COVID period. The study supports the clarion call on university teachers involved in virtual teaching to personally seek a continual update of skills and competency in virtual delivery because it is an approach hinged on evolving technology.