Pres. Obama’s address to the nation aired on the big four networks last night. Not surprisingly, the two networks that had original reality programs airing at 8pm, ended up with the most viewers.

MediaLife has the A18-49 time-period ratings, live-plus-same-day DVR, from last night: of the networks airing the president’s address at 8pm, NBC was first with a 2.9 for Obama and the “The Voice,” Fox drew a 1.9 for Obama and “So You Think You Can Dance,” ABC had 1.1 for the address and repeats of “The Middle,” and CBS had a 1.0 for Obama and a repeat of “Undercover Boss.”

While NBC won the hour, Univision was actually second in the demo with a 2.6 rating. The network was airing a Gold Cup soccer match between the U.S. and Canada. Other notes:

• ABC’s first “Primetime Nightline” featuring the Casey Anthony case came in third place in the A18-49 demo (1.3) at 10pm behind NBC’s “America’s Got Talent” and soccer on Univision.
• On FOX’s “So You Think You Can Dance” judge Nigel Lythgoe addressed the delayed start of the live show due to Obama’s troop draw-down announcement after a performance that portrayed a soldier coming home from war to his wife.