The track is likely to surge on next week's charts following its first full week of tracking and become Marshmello's 10th Hot Dance/Electronic Songs top 10 and Lovato's third.
Concurrently, "OK" bows at No. 5 on the Dance/Electronic Digital Song Sales chart, becoming the masked DJ's 13th top 10 and likewise the singer's third.
Elsewhere on Hot Dance/Electronic Songs, Jackson Wang registers his first appearance, and Galantis earns its 25th, with the No. 12 arrival of "Pretty Please" (1.6 million streams, 1,000 sold).
Additionally, Sigala earns its highest rank among 10 appearances with the No. 14 start of "Lasting Lover," featuring James Arthur, as it opens with 913,000 streams and 2,000 sold.