Country king Kenny Chesney grabs his seventh No. 1 album on the Billboard 200 chart as Life on a Rock debuts atop the list. The set sold 153,000 copies in its first week, according to Nielsen SoundScan.

Among country acts with the most No. 1s on the Billboard 200, Chesney is second to only Garth Brooks. The latter notched eight leaders between 1991 and 2001.

Since 2004, all 10 of Chesney’s regular full-length albums have debuted in the top four on the Billboard 200. His latest follows 2012’s Welcome to the Fishbowl, which debuted and peaked at No. 2 with a 193,000 start. The new album’s debut week is his smallest sales bow for a studio set since 1999’s Everywhere We Go began with 30,000.

The first single from Life on a Rock, “Pirate Flag,” became his 45th top 10 hit on the Country Airplay chart in March. This week, the tune rises 5-4.

Chesney’s new album is one of only two debuts in the top 10 this week, as fellow country act Randy Rogers Band’s Trouble also enters at No. 9, with 26,000. It follows the group’s last album, 2010’s Burning the Day, which debuted and peaked at No. 8 with 29,000 in its first week.

Over on the Country Albums chart, Chesney and Randy Rogers Band arrive at Nos. 1 and 3, respectively. It’s Chesney’s 12th No. 1 set on that tally.

Back on the Billboard 200, last week’s No. 1, Michael Bublé’s To Be Loved, slips to No. 2 in its second week with 96,000 (down 51%). It’s the smallest second-week percentage decline for a No. 1-debuting album since Josh Groban’s All That Echoes fell by just 50% on the chart dated March 2. More recently, albums that bowed at No. 1 from the likes of Paramore, Fall Out Boy and Bon Jovi all tumbled by more than 70% in their second weeks.

Behind Bublé this week is Justin Timberlake’s The 20/20 Experience, which holds at No. 3 with 68,000 (down 8%). 20/20 has spent its entire seven-week chart run lodged in the top three: Its first three weeks were at No. 1, followed by four straight frames at No. 3.

Fantasia’s Side Effects of You falls 2-4 in its second week with 36,000 (down 60%) while Macklemore & Ryan Lewis’ The Heist rises 11-5 with 35,000 (up 24%). The set’s second single, “Can’t Hold Us,” has been inescapable in TV commercials for Microsoft Outlook lately, while it also continues to climb the Pop Songs airplay chart. The track, which features Ray Dalton, climbs 7-5 on Pop Songs (known as Mainstream Top 40 on Billboard.biz) with a 25% gain in plays on top 40 stations.

Blake Shelton’s Based on a True Story . . . remains at No. 6 with nearly 35,000 (down 3%), P!nk’s The Truth About Love rises 10-7 with 26,000 (though down 8%), and Bruno Mars’ Unorthodox Jukebox ascends 13-8 with almost 26,000 (up 4%). Closing out the top 10 is Imagine Dragons’ Night Visions, jumping 15-10 with 25,000 (up 14%).

Over on the Digital Songs chart, things are pretty static in the top 10, as the entire top three is stationary, while only one title moves into the top 10.

Macklemore & Ryan Lewis’ “Can’t Hold Us” is steady at No. 1 again (262,000; up 1%), as is P!nk’s “Just Give Me a Reason” (featuring Nate Ruess) at No. 2 (255,000; up 1%) and Justin Timberlake’s “Mirrors” at No. 3 (176,000; up 1%).

Florida Georgia Line’s “Cruise” is up one slot to No. 4 (145,000; up 6%), Rihanna’s “Stay” (featuring Mikky Ekko) is down a rung to No. 5 (140,000; down 14%), and Icona Pop’s “I Love It” rises 7-6 (136,000; up 2%). Imagine Dragons’ “Radioactive” slips 6-7 (134,000; down 1%), Macklemore & Lewis’ “Thrift Shop” stays at No. 8 (117,000; down 11%), and Selena Gomez’s “Come & Get It” hits the top 10 for the first time, climbing 14-9 with 115,000 (up 27%). Closing out the top 10 is Mars’ “When I Was Your Man,” descending one position to No. 10 with 109,000 (down 6%).

Overall album sales in this past chart week (ending May 5) totaled 5.1 million units, down 1% compared with the sum last week (5.2 million) and down 11% compared with the comparable sales week of 2012 (5.8 million). Year-to-date album sales stand at 100.8 million, down 6% compared with the same total at this point last year (106.7 million).

Digital track sales this past week totaled 24.2 million downloads, down 1% compared with last week (24.3 million) and down 5% stacked next to the comparable week of 2012 (25.4 million). Year-to-date track sales are at 482.5 million, down 3% compared with the same total at this point last year (495.4 million).

Next week’s Billboard 200 competes with the same week in 2012 when: Carrie Underwood’s Blown Away held at No. 1 for a second week with 120,000 (down 55%), while Silversun Pickups’ Neck of the Woods was the chart’s highest debut. It arrived at No. 6 with 41,000. [Billboard.biz]