Evan Ferguson scored a brace as Brighton beat Grimsby 5-0 to progress to the semi-final of the FA Cup.
The 18-year-old Irishman scored his side's second and third goal on a comfortable afternoon for the Seagulls.
Roberto de Zerbi's side will now face either Manchester United or Fulham in the semi-final at Wembley.
Town were just the fifth tier-four team in competition history to reach this stage and were hoping to accomplish what none had done before by beating their commanding Premier League opponents.
The Seagulls’ upcoming trip to the semi-finals will be just their third and leaves them in contention to reach their first trophy contest since 1983.
Grimsby Supporters – over 4,500 of them, many brandishing the Mariners’ signature inflatable Harry Haddocks – flocked to the Amex Stadium, where home supporters responded with plastic seagulls.
It was always going to be a tough ask of Town, who sit 76 places lower than Sunday’s opponents in the pyramid. Grimsby had beaten Southampton to get here, but Roberto De Zerbi’s Brighton, with their eyes on Europe, were a different calibre.
Ferguson tested Max Crocombe inside the first two minutes with a low strike from just inside the area, which the visiting goalkeeper coolly stooped to collect.
Grimsby enjoyed a brief spell in the hosts’ half before Brighton were on the attack again, patiently passing before eyeing up the best opportunity to net an opener.
Moises Caicedo thought that moment was his when he fired a sharp low effort from centre but was instead denied by Crocombe, who was there to make the save but fumbled the stop, allowing the awaiting Undav to pounce and bury the rebound inside six minutes.
The school of Mariners’ supporters were undeterred, growing louder when their side earned a handful of inconsequential set-pieces, and Anthony Driscoll-Glennon put in a good sliding tackle to clear Mitoma’s effort from a tight angle – though it ultimately looked destined to go across the face of goal.
Crocombe blocked Undav’s attempt to nod in March’s cross as Albion remained on the attack, the hosts coming close when Pascal Gross – from the right of the area – sent a delivery to Mitoma at the far post.
The Japan international stretched out to toe the ball in but instead directed it wide from six yards out.
Several subsequent attempts via Mitoma, Caicedo and Pascal Gross all failed to find the back of the net and the visitors did well to break up Mitoma’s run in added time to give themselves a chance after the restart.
Instead, the early chance fell to Brighton when March’s cross from the left flank clipped the left post and the ball bounced to Undav, who misfired off his unfavoured left foot.
It was not long, however, before the hosts made it two. Alexis Mac Allister found Ferguson, his back to goal, who in a skilful move brought the ball down with his left foot, transferred it to his right on the pivot and fired home.
Ferguson completed his brace when he was slipped the ball by Undav, setting up the Republic of Ireland international for a simple finish as he directed the ball into the bottom-left corner.
March sent a header past Crocombe after 82 minutes, which looked to seal the scoreline before Mitoma ensured he was involved in a goal in each of his four FA Cup appearances this season, firing home Brighton’s fifth in the final minute of normal time.
