As the English-language broadcast networks are in full holiday mode with schedules dominated by reruns, Univision is taking advantage. For a second consecutive year, the top Spanish-language broadcaster is posting nightly wins in late December. After finishing tied with NBC for No. 1 among adults 18-49 last Friday, Univision (1.3/4 in 18-49, 3.4 million total viewers) was alone in the top spot last night. A Christmas-themed Chuck (1.0/4) on NBC was the only original offering on the English-language networks. It was up a tenth from last week.