"We've never played with the three strikers like that before," Tabarez told reporters. "We felt we had to go for it and it worked out for us.
"We pressed really well at the start and then Nigeria gained control through to the second half, when we took the lead and stayed solid at the back. We could have killed the game off earlier but we're very pleased all the same.
"Since the draw was made we've been saying this was our big game. We've taken a step towards the semi-finals. We're not there yet, but we've smoothed the path."
Uruguay, who lost to Spain in their opening game, take on Tahiti in their final match of Group B on Sunday.