The #1 on M Countdown on 2021-04-15 was “One” by Astro — win No. 3 for the song and career win No. 5 for Astro (No. 1 on this show). It also won The Show, Show Champion the same week (3 crowns).
“One” has 3 music show wins in total: 2021-04-13 The Show, 2021-04-14 Show Champion, 2021-04-15 M Countdown. Astro had 3 wins in 2021 up to this date, and this was the artist's first win on M Countdown. The previous week's M Countdown #1 was “On the Ground” by Rosé. The other shows that week went to Music Bank: “Lilac” by IU; Show! Music Core: “Lilac” by IU. Episode data comes from broadcasters' published results (Wikipedia lists, CC BY-SA) and is recounted daily.
| Date | Show | Song · Artist | |
|---|---|---|---|
| 2021-04-13 | The Show | OneAstro | ★ #1 |
| 2021-04-14 | Show Champion | OneAstro | ★ #1 |
| 2021-04-15 | M Countdown | OneAstro | ★ #1 |
| 2021-04-16 | Music Bank | LilacIU | ★ #1 |
| 2021-04-17 | Show! Music Core | LilacIU | ★ #1 |