Brazil forward Neymar left the field in tears after Santos suffered a 6-0 home defeat by Vasco da Gama.
The loss was the biggest of Neymar’s career and it was the first time that Santos have conceded six goals at home in a Brazilian Serie A match.
The eight-time champions are two points above the relegation zone and coach Cleber Xavier was sacked hours after Sunday’s game.
Former Liverpool and Aston Villa forward Philippe Coutinho scored twice as Vasco claimed their first win in six league games and their biggest league win in 17 years.
“I’m ashamed,” said Neymar. “I’m totally disappointed with our performance. The fans have every right to protest, obviously without using violence.
“But if they want to curse and insult, they’re in their right. To sum up our attitude on the field, it was terrible.
“I’ve never experienced this in my life. The tears were from anger, from everything. Unfortunately, I can’t help in every way.
“I think everyone today needs to go home and think about what they want to do.”
Neymar remains the world’s most expensive footballer, joining Paris St-Germain from Barcelona for £200m in 2017, and he returned to his boyhood club in January after the termination of his contract with Saudi Pro League side Al-Hilal.
The 33-year-old signed another six-month deal in June and since rejoining Santos has claimed six goals and three assists from 21 games in all competitions.
Brazil’s all-time leading goalscorer left the field in tears after getting injured 34 minutes into his first Serie A start of the season, before missing the next five league games with a hamstring problem.
Xavier, 61, took charge at the end of April after serving as an assistant manager at several Brazilian clubs, plus the national team.
Santos won five of his 15 games in charge and are now just two places above the relegation zone, just a place higher than Vasco who were lifted out of the bottom four after Sunday’s win.
Santos won promotion back to the Brazilian top flight last November after spending a year in Serie B following their first ever relegation.
Their next game is away to fourth-placed Bahia on Sunday, 24 August.
