There's nothing like a basketball matchup between the Boston Celtics and the Los Angeles Lakers to lift TV ratings -- and Thursday's coverage on ABC did just that in spades. Game 1 of the NBA finals, played in Los Angeles, averaged 11.7 million viewers and won every half-hour in primetime between 9 00 p.m. and 11 00 p.m., then went on to score even a greater number of viewers in the 11 00 p.m. hour. The telecast's audience was down from the 13.04 million who tuned in to Game 1 of last year's finals between the Lakers and the Orlando Magic. A two-hour edition of Fox's summer talent series So You Think You Can Dance won the 8 00 p.m. hour but fell to second place at 9 00 p.m. behind the basketball contest. Meanwhile, NBC, which once dominated Thursday nights, saw its numbers fall again -- perhaps to their lowest ever for what the network once called "Must See TV" night. Its new 8 30 p.m. sitcom, 100 Questions, could only find 2.23 million viewers.