Brighton lost a chance to advance in the European competition after being held to a Premier League draw at Selhurst Park by rivals Crystal Palace.
Influential visitor Solly March got ahead of Tyrick Mitchell at the back post to direct Pervis Estupinan's searching delivery into the top corner, giving the visitors the lead.
Six minutes later, the hosts equalized when Seagulls goalkeeper Robert Sanchez made an obvious error by failing to make a routine catch of Michael Olise's cross, allowing James Tomkins to head home from close range.
With two games remaining, the outcome puts Palace in 12th place and Roberto de Zerbi's Brighton four points (and two games remaining) behind fifth-placed Tottenham, who were soundly defeated by Leicester on Saturday.
The Seagulls will look back on this game with regret, though, as they were the team that created the majority of the excellent scoring opportunities.
After scooping a right-footed finish past Palace goalkeeper Vicente Guaita during an exciting but scoreless first period, Estupinan was judged to be just barely offside by VAR.
Brighton's easygoing manner stood in stark contrast to the hosts' attempt to make it a competitive event. .
While all three of Palace's best chances—two blocked Jean-Philippe Mateta shots and Tomkins' goal—came as a result of their opponents' errors, it was still enough for them to secure a spirited draw.
Brighton paid for errors made on both ends.
While Brighton extended their unbeaten streak to seven games across all competitions, they would have had a better chance of climbing the league standings had they been able to claim the victory that their play merited.
If their finishing had been as creative and proficient as their build-up play, they might have been out of sight by halftime.
After serving his suspension, Alexis Mac Allister of Argentina engaged in a one-on-one battle with Guaita. Guaita expertly denied him three times and also showed off his agility to stop in-form winger Kaoru Mitoma from scoring four goals in as many games.
In the closing minutes, when it seemed easier to score, Adam Webster and Mac Allister both headed wide from excellent positions.
Palace should be commended for their tenacity in staying in the game despite managing just one attempt on target and only 25% of the possession.
The team led by Patrick Vieira fought and hustled for every loose ball, and Tomkins, captain Marc Guehi, and Guaita were crucial to their comeback.