CBS announced today that “The Late Show with Stephen Colbert” accomplished a ratings first during the week ending March 31. Citing Nielsen L+SD data, the network noted that along with claiming a win in total viewers for the ninth consecutive week, “Colbert” tied for first in the 25-54 demo for the first time in the show’s history.

It doesn’t have quite the same impact that a win in the key advertiser-friendly demo of viewers 18-49 would have, but so far “Colbert’s” chief rival, NBC’s “Tonight Show starring Jimmy Fallon,” has been able to hang on to the top spot in that metric.

CBS also noted that “Colbert” won the week in total viewers by more than 400,000, its largest advantage since the show’s premiere week back in September 2015.

For the week ending March 31, the show was up 33% both in total viewers (2.99 million) and in adults 25-54 (0.8 rating/4 share) from a year ago. The show’s nine-week winning streak in total viewers marked the first such streak for CBS in late-night since the weeks of Nov. 20, 2009, to Jan. 15, 2010.

“Colbert” also closed the gap on “Fallon” in the 18-49 demo, delivering a 0.5 rating/3 share, up 25% from a year ago, to come within 0.1 ratings point, matching its closest competitive position.