Tariq Lamptey and Steven Sessegnon both convert, so we're still all square after six penalties.
Job done for Manchester United.
A professional performance sees Erik ten Hag's team go through to the League Cup quarter-finals as the Dutch manager looks to end the club's barren run without a trophy.
Quality finishing from the Premier League side proves the difference.
Solly March has the chance to win it for Brighton... but blazes over.
Corey Blackett-Taylor then holds his nerve to stick it in the corner and make it 2-2, sending it into sudden death.