The special, which pitted Olympics gold winning swimmer Michael Phelps against a great white in a swimming competition, was the highest-rated "Shark Week" telecast ever across several demos, including adults 25-54, women 25-54, and women 18-49, said network officials.
All told, "Phelps vs. Shark" hauled in more than 5 million total viewers, on average.
The July 23 premiere of Shark Week also was the highest live and on-demand streaming day on Discovery Go. "Great White" led Discovery to finish No. 1 across basic cable's primetime.
While drawing record ratings, the episode was not without controversy. Discovery and Michael Phelps both defended the special after some viewers reacted angrily, complaining that it wasn't a real shark and they felt duped by promos for the episode.
Buffalo is at least 500 miles from nearest saltwater shoreline, but its apparent love affair with sharks endures, as evidenced by the local popularity of "Shark Week" on the Discovery Channel. All the promotion, interviews and the program itself made clear that the challenge wasn't a side-by-side race.