Mason Stephens gave the hosts an early lead, but Greenwood brought the Blues level on the half-hour.

Andrew Pennie put Dan Hogan’s side ahead shortly after the interval before Greenwood added a penalty and completed his treble late on.

Heze Grimwade rounded off the scoring in the final minute of normal time, finishing from goalkeeper Toby Bell’s long ball forward.

Brighton went ahead after eight minutes, Stephens beating Bell with a low finish after being through one-on-one.

Chelsea’s first effort came through Jacob Hall, whose left-footed shot from outside the area was saved. Pennie then fired wide and had another attempt blocked before Greenwood struck just over.

The equaliser arrived in the 30th minute. Charlie Wilson-Papps could not hold Grimwade’s low cross after a slick passing move and Greenwood followed up to finish from close range.

Grimwade had a shot from distance charged down before the break, with the sides going in level.

Second-half rout

Grimwade tested Wilson-Papps with a free-kick two minutes after the restart and was denied again shortly afterwards, his right-footed effort saved low.

The Blues moved ahead in the 53rd minute when Brighton failed to clear their lines and Pennie was there to apply the finish.

Wilson-Papps continued to keep Chelsea out, pushing away Eden Mahoney-Smith’s low strike before saving Grimwade’s effort from a tight angle at the foot of the post.

Our third came with 20 minutes remaining. Fraser Widdop brought down Grimwade inside the area and Greenwood converted the penalty into the bottom corner.

Isago Silva replaced Hall in the 74th minute, with Trey Faromo-Adebayo coming on for Pennie a minute later.

Greenwood completed his hat-trick three minutes from time, his cross-shot taking a deflection off Frankie Pope and looping into the far corner.

Wilson-Papps denied him a fourth at the near post, but Chelsea added another in the 90th minute. Bell’s long kick sent Grimwade through and he rounded the goalkeeper to finish right-footed into the bottom corner.

What it means

The Blues are fourth in the Under-18 Premier League South table after three wins from our five games so far, meaning we are four points below leaders Tottenham Hotspur.

What’s next?

Chelsea Under-18s host Bournemouth in the Under-18 Premier League at Cobham Training Centre on Saturday 19 September. Kick-off is at 11am UK time and you can watch the match live on CFC+.

The teams

Chelsea: 1. Toby Bell, 2. Gabriel Sambou, 3. Josh Henry, 4. Dante Waite, 5. Jacob Hall (14. Isago Silva 74), 6. Isaac Badu Da Silva, 7. Eden Mahoney-Smith, 8. Jacob Dako, 9. Jashayde Greenwood, 10. Heze Grimwade, 11. Andrew Pennie (17. Trey Faromo-Adebayo 75)
Unused subs: 12. Emmanuel Ayinde, 13. Aaron Woolford, 15. Jayden Malundama, 16. Isaac McGillvary, 18. Kwamina Ampah
Scorers: Greenwood 30, 70 (pen), 87, Pennie 53, Grimwade 90
Booked: Hall 41, Pennie 59, Badu Da Silva 78
Manager: Dan Hogan

Brighton & Hove Albion: 1. Charlie Wilson-Papps, 2. Finley Cooper, 3. Daniel Nneji, 4. Jake Evans, 5. Chetam Ezenwata (15. Frankie Pope HT), 6. Zac Brennan (14. Brook Smith 62), 7. Mason Stephens (17. Fraser Widdop HT), 8. Louie Hartshorn (12. Raffaele Oppong 71), 9. Jacob Parsons (16. Chris Condy 66), 10. Finn Dzekawong, 11. Daniel Rudin
Unused subs: 13. Liam Doyle, 18. Brodie Felton
Scorers: Stephens 8
Booked: Rudin 80, Cooper 90+2
Manager: Carl Martin