‘WHO Wants to Be a Millionaire” returned to prime time Sunday night.

But, this time around, the results weren’t nearly as spectacular.

The first of “Millionaire’s” 11-night return with original host Regis Philbin averaged 6.9 million viewers — good for second in total viewers (8-9 p.m.) behind CBS’s “Big Brother.”

But “Millionaire,” celebrating its 10th anniversary, finished a distant fourth in the advertiser-coveted adults 18-49 demo.

That’s quite a change from its heyday, when “Millionaire” routinely averaged over 30 million viewers before eventually losing its mojo.