Only one of the evening newscasts posted year-to-year growth in total viewers and the key news demo of adults 25-54 during the first quarter of 2011. That newscast was ABC’s “World News With Diane Sawyer,” according to a press release from ABC.

“World News” also had double-digit increases in both categories over he previous quarter, the network reported. As a result the network narrowed the gap significantly between itself and leader NBC.

During the first quarter of 2011, the ABC telecast averaged 8.65 million total viewers and a 2.0 rating/7 share/2.43 million among adults 25-54, according to Nielsen Media Research, the network reported. That represents an improvement of 4% in total viewers and 2% in the 25-54 demo over the year-ago period. NBC’s “Nightly News” was down 1% and 3% in the two categories, respectively, while CBS’s “Evening News” was flat and down 2%.

“World News” narrowed its margins against “Nightly News” from the year-ago period by 30% in total viewers (1.16 million vs. 1.65 million) and 19% in adults 25-54 (510,000 vs. 630,000), ABC reported.

The ABC telecast also outperformed CBS’s “Evening News” by 2.22 million total viewers and by 450,000 adults 25-54 during the first quarter of 2011, ABC said.