Harry Kane's 26th league goal of the season could not get Spurs back to winning ways as Brighton earned a deserved 1-1 draw at the Amex Stadium.
His close-range finish, three minutes after half-time, was harsh on the Seagulls who had limited the visitors' forward line before the break.
Brighton were handed an opportunity to level within moments of the opener when Serge Aurier bundled Jose Izquierdo over in the box, and a hand from Hugo Lloris was not enough to keep out Pascal Gross' powerful spot-kick.
The draw takes Brighton eight points above the bottom three, while the result gives Chelsea a small chink of light for a top-four spot, with Tottenham eight points clear of the Blues having played a game more.
Brighton's air of confidence was not what you would expect from a side four games without a win. They gave Hugo Lloris a scare when he fumbled Lewis Dunk's header but the Frenchman gathered before he was punished.
Lloris' errors have cost Spurs three goals in as many games but there was nothing too testing about Brighton's efforts before half-time, and Matt Ryan was the busier goalkeeper, tipping a long-range effort from Lucas Moura and Heung-Min Son's low shot behind.
Kane had been off-colour before the break, slipping as he fired a free-kick over and also finding row Z with a wayward long-range strike, but he did what he does best three minutes after the break.
Son did excellently to keep the ball in when it ricocheted off Lucas Moura, out-muscling Dunk before beating Ryan to the ball and inadvertently finding Kane, who smashed into the net via a deflection off Bruno.
Brighton needed just 18 seconds after the restart to find a route back into the game, when Izquierdo received a lovely reverse pass from Glenn Murray and was knocked to the floor by Aurier's clumsy challenge.
Gross stepped up with Murray taken off penalty duties and smashed the ball beyond Lloris despite the France international's best efforts.
Tottenham responded with Lucas Moura missing the near post and Shane Duffy diverting Christian Eriksen's cross just beyond the far one with little idea where the ball would end up, but dropped points for the second game in succession to fall off the pace in the race for second place.
The Managers
Chris Hughton: "It's a step [towards safety]. What I was most happy with was our character. To concede when we did, probably through our own fault, to react as we did and play as big a part in the game as we did, I thought we showed great character and quality when we had to.
"We spoke about having to give everything against these sides, and if you're that percentage below your best, they can really hurt you. It's concentration, not allowing the quality they've got and I think we limited them to chances but no real clear ones."
Mauricio Pochettino: "In the second half we created chances, but not enough to win the game. We tried to give the team some fresh legs, playing in the evening on Saturday was so tough mentally and physically, and we needed to rest some players and rotate.
"I think we have the squad to win games, and we rotated the team. I think the most important thing is the big picture, we have a big squad, everyone is ready to play, the game was tough, Brighton were a difficult opponent, and we have to congratulate them."
Match facts
- Tottenham failed to win a league game in which they were ahead for only the second time this season (W20 D2 L0), with the other game being a 1-1 draw with Burnley in August.
- There were just 143 seconds between Harry Kane's opener and Pascal Groß's leveller.
- Groß has been directly involved in 43.8% of Brighton's 32 Premier League goals this season (6 goals, 8 assists). Only Mo Salah (50%) has been involved in a higher proportion of his team's goals.
- No side has drawn more home games this season than Brighton (8, level with West Brom).
- Tottenham are unbeaten in 13 away games in all competitions - only once have they ever had a longer run (15 between April 1949 and January 1950).
- Harry Kane has now scored against 26 of the 27 different clubs he's faced in the Premier League (96.3%), with the exception being Cardiff City.
- Of all players to have played against more than one side in the competition, only Thierry Henry (97.1%) and Sergio Aguero (96.9%) have scored against a higher percentage of the opponents they've faced.
- The English striker has now scored 15 away goals in the Premier League this season - only Kevin Phillips in 1999-00 (16) has scored more on the road in a single campaign.
Man of the match - Pascal Gross
Continued his exceptional season of being involved in more than 43 per cent of Brighton's goals this season, with six goals and eight assists.
He took responsibility for their penalty after Glenn Murray missed two earlier in the season, and struck it confidently past Lloris to level.
Gross was also impressive from set-plays, providing nine crosses during the game and making two key passes - second only to Eriksen among either side.
What's next?
Spurs are back on the trophy hunt on Saturday when they take on Manchester United in the FA Cup at Wembley (5:15pm kick-off). Brighton are out of action until they travel to Burnley on April 28.