UPDATE PM: ABC dominated Thursday night with the 2010 NBA Finals Game 1 between the Los Angeles Lakers and Boston Celtics, (5.7 rating/18 share in adults 18-49, 14.1 million viewers overall), which ranked as the most watched NBC Finals opening night ever. The Jimmy Kimmel Live Game Night special (1.3/5, 4.2 million) also hit an all-time high.

PREVIOUS AM: Game 1 of the NBA finals was the main attraction on Thursday, helping ABC dominate the night. While accurate time-adjusted numbers for the game won’t be available until the afternoon, the ratings for the opening game between LA Lakers and Boston Celtics (4.5 rating/13 share among adults 18-49 in the fast nationals) are expected to be in line or even a bit higher than last year’s finals opener between the Lakers and Orlando Magic, which posted the top Game 1 numbers in 5 years. In the home towns of the two teams, the game drew 25.2/43 (Los Angeles) and 19.1/34 (Boston) household ratings in the metered markets.

In its third airing this summer, Fox’s So You Think You Can Dance (3.2/10 in 18-49) hit its best numbers of the season. The other networks aired repeats with the exception of NBC’s summer burnoff comedy 100 Questions (0.9/3), which was up a tenth in its second airing but still ranked as the lowest-rated program on the Big 4 networks last night.