JOSHUA King’s first goal of the season booked Cherries a place in the last 16 of the League Cup for the third time in the past four seasons.

King came off the bench to settle the tie with a finely-taken winner in the ninth minute of extra-time.

In truth, it was no more than Cherries deserved with Eddie Howe's team having dominated possession and chances throughout.

Cherries will discover their fourth round opponents when the draw is made tomorrow, with the clash taking place during the week commencing October 23.

The Dorset club has reached the quarter-final once in their history, bowing out to Liverpool at Dean Court in 2014-15.

As expected, both managers made wholesale changes with only three players remaining in the respective starting line-ups from Friday’s Premier League meeting.

For Cherries, Ryan Fraser and Simon Francis kept their places, while Liam Rosenior was Brighton’s only survivor and skippered the Seagulls.

Cherries welcomed back defender Steve Cook, who recovered from a knee injury, while there was a return for Junior Stanislas, who was involved for the first time this season.

Jose Izquierdo fashioned the first shooting chance for the visitors, forcing Cherries goalkeeper Artur Boruc to beat away his thunderous drive after six minutes.

Lys Mousset then tried his luck from the distance, although the Frenchman’s low drive failed to trouble Brighton stopper Tim Krul, who saved comfortably.

Mousset blazed a presentable opening high over the crossbar after Benik Afobe had shown great tenacity to dispossess defender Rosenior.

A burst of pace from Jordon Ibe took him past Jayson Molumby, only for the winger to drill his shot way off target.

Mousset warmed Krul’s hands with a ferocious effort from 25 yards, which the goalkeeper pouched low down diving to his right.

Cherries had an escape midway through the first half after Jiri Sklak’s angled drive had been spilled at his near post by Boruc.

However, after Jamie Murphy attempted to pounce on the loose ball, Boruc smothered at his feet to foil the Seagulls striker.

Cherries appealed in vain for a penalty after Afobe had gone to ground following a coming-together with Uwe Hunemeier.

Izquierdo weaved his way through after 35 minutes, the Colombian’s resultant shot trickling across the face of the goalmouth.

Cherries created the clearest opportunity on the stroke of half-time when Ibe’s fizzing low drive was pushed around the post by Krul.

And just minutes after the restart, a flurry of activity in the Brighton 18-yard box saw Cherries again go close to breaking the deadlock.

Firstly, Mousset’s fierce drive was blocked before Afobe’s header looped to the far post where Stanislas followed up to hit the post from close range.

Boruc then came to Steve Cook’s rescue after the defender had made a hash of a back-pass, the goalkeeper saving Murphy’s shot after he had seized on the error.

Stanislas again showed his rustiness in front of goal when he ballooned his shot over the crossbar following a blistering run and centre from Ibe.

Lewis Cook’s 25-yard piledriver was turned around the post by Krul before Mousset’s header was nodded off the line from the resultant corner.

As Cherries went in search of a late winner in normal time, Afobe was denied by Krul after taking aim from 16 yards, a shot from Marc Pugh was charged down and Fraser’s low drive was snaffled by the Brighton stopper.

At the start of the first period of extra-time, Lewis Cook’s shot cannoned off Afobe and flew over the crossbar before Afobe turned a cross from Joshua King past the upright.

Ibe saw his goalbound effort strike defender Goldson before Cherries’ pressure finally told when King opened the scoring in the 99th minute.

The substitute took a pass from Pugh, jinked his way past a couple of challenges and placed the ball past Krul from close range.

Gaetan Bong escaped after appearing to handle inside the penalty area, while substitute Adam Smith dragged a shot wide in the second period of extra-time. 

Cherries: Boruc, Fraser (Hyndman, 117) , Francis, S Cook, B Smith, Ibe (A Smith, 103), Gosling, L Cook, Stanislas (Pugh, 63), Mousset (King, 79), Afobe.

Unused subs: Simpson, Mahoney, Ramsdale (g/k).

Booked: Boruc.

Seagulls: Krul, Hunemeier, Goldson, Rosenior (Mateju, 110), Schelotto (Propper, h-t, e-t), Hutchinson, Molumby, Bong, Skalak (March, 103), Murphy, Izquierdo (Knockaert, 103).

Unused subs: Dunk, Tilley, Maenpaa (g/k).

Booked: Skalak.

Referee: Kevin Friend (Leicestershire).

Attendance: 10,163 (including 652 visiting supporters).