Chelsea suffered their first defeat against Bournemouth for the first time since 1988 at the Vitality Stadium.
Maurizio Sarri handed a debut to new signing Gonzalo Higuain but Callum Wilson missing for the home side.
Both teams started brightly on the South coast, but Chelsea soon began to establish some dominance and came agonisingly close to taking the lead in the seventh minute when Artur Boruc somehow managed to tip Mateo Kovacic’s header from close range onto the crossbar.
Chelsea remained in the ascendancy with Eden Hazard’s seeing a 20-yard strike well dealt with by Boruc, and it took until the 21st minute for Bournemouth to register their first shot with Andrew Surman firing over from distance.
Pedro should have done better at the other end when cutting inside onto his left foot and only shooting straight at Boruc, and Bournemouth finally began to threaten after the half-hour mark with David Brooks heavily involved.
The Wales international failed to convert from 10 yards before seeing a weak header easily saved by Kepa Arrizabalaga, and the playmaker fared no better with a 25-yard strike after a run from the halfway line.
Cesar Azpilicueta attempted to hit back for Chelsea and had a left-footed effort tipped away by Boruc, before a Bournemouth counter-attack ended with Junior Stanislas drilling a first-time attempt straight at Arrizabalaga.
The action did not let up after the restart and Bournemouth required less than 90 seconds to take the lead. Brooks caught the Chelsea backline napping by making a run in behind from a throw-in, and the Welshman cut the ball back for King to lash a shot into the roof of the net from 12 yards out.
Chelsea rallied after going behind but they were struggling to find any space in a congested final third, with only a long-range effort from Pedro threatening an equaliser.
The visitors then proceeded to gift their hosts a second goal. A mix-up on the halfway line between David Luiz and Antonio Ruidger let in Brooks and after the midfielder was played through on goal by King, the Welshman cut inside Luiz before forcing the ball into the bottom corner from 10 yards.
Chelsea were starting to be outclassed by Eddie Howe’s men, but it got worse in the 74th minute as Stanislas was played through on goal before teeing up King to send the ball into the top corner of Arrizabalaga’s net from close range.
The game was over as a contest, but Chelsea continued to search for a consolation goal with Ruben Loftus-Cheek failing to hit the target from inside the penalty area and Rudiger having a close-range header saved by Boruc.
Bournemouth appeared happy to settle for the third goals but in the final minute of added-on time, Daniels added a fourth for the home side as he stopped down to head Jordon Ibe’s cross past a helpless Arrizabalaga.