On the Billboard album chart, Dua Lipa’s heavily promoted “Radical Optimism” opened at No. 2, held off by the third week of Taylor Swift’s “Tortured Poets.”An old-fashioned rap war that unfolded online at lightning speed has sent Kendrick Lamar to No. 1 on Billboard’s latest singles chart, while Taylor Swift easily holds off a challenge from Dua Lipa’s new album.Relations between Lamar and Drake, two hip-hop giants and longtime rivals, exploded into a public war of words in recent weeks, in the form of a rapid-fire sequence of diss tracks packed with insults and unsavory (and unproven) accusations. Lamar seemed to get the last word with “Not Like Us,” released May 4, which becomes his fourth No. 1 on Billboard’s Hot 100 singles chart. That total counts collaborative releases — among them “Like That,” a track in March with the Atlanta rapper Future and the producer Metro Boomin, which kicked off the latest volley.Consumption of “Not Like Us” was driven by streaming, with 71 million clicks in the United States last week. Another Lamar diss track, “Euphoria,” which came out the week before, is No. 3 on the latest singles chart, while Drake’s “Family Matters” is No. 7.For this week’s Billboard 200 album chart, Lipa seemed to enter the contest with some advantages for “Radical Optimism,” her third studio LP. To promote it, she went on “Saturday Night Live” as both performer and host, and was on the cover of Time and Elle. Earlier this year, she had prominent performances at the Grammy and Brit award shows, and appeared on the cover of Rolling Stone.But “Radical Optimism” was still trounced by the third week of Taylor Swift’s “The Tortured Poets Department,” which holds at No. 1 with a wide margin.“Tortured Poets” had the equivalent of 282,000 album sales in the United States, including 298 million streams and 51,000 traditional sales, according to the tracking service Luminate. In its first three weeks out, “Tortured Poets” — which smashed records in its debut two weeks ago, despite mixed reviews — has racked up the equivalent of 3.3 million sales, including 1.6 billion streams for its 31 total tracks in the U.S. alone.We are having trouble retrieving the article content.Please enable JavaScript in your browser settings.Thank you for your patience while we verify access. If you are in Reader mode please exit and log into your Times account, or subscribe for all of The Times.Thank you for your patience while we verify access.Already a subscriber? Log in.Want all of The Times? Subscribe. More