Enzo Le Fée's first-half penalty proved decisive as Sunderland claimed their second Premier League victory of the season, leaving Chelsea frustrated after failing to turn their possession and territorial advantage into clear-cut opportunities.
Chelsea enjoyed more control after the interval, but struggled to break down a disciplined Sunderland defence that committed players behind the ball to protect its lead.
Penders was largely untroubled during the contest, although he produced an important second-half save to deny Wilson Isidor. However, the goalkeeper was left disappointed by the outcome and acknowledged the difficulty of playing against Sunderland's aggressive approach.
“Very disappointed with the result,” Penders said. “You know when you come here to their stadium that it will be a difficult game, and they fought very hard.
“At one point, it went very fast from side to side. Sometimes we had control and, of course, in certain moments when you go higher up the pitch they will be very aggressive and the way they play is very difficult.
“In the second half they dropped very low and had every man behind the ball, so we had a bit more control and we had to push. We had some chances, but it was difficult against 11 behind the ball to find the right spaces.
“We kept pushing, especially in the last 15 minutes, we kept dropping balls at them, but it wasn’t enough.”
The defeat came at an inconvenient point in the campaign, with Chelsea now facing an international break before returning to action against Leeds United on November 21.
Penders believes there have been encouraging signs in the team's recent performances, particularly in the development of its structure, and does not want one disappointing result to undermine the progress being made.
“If you watch some of the last games, we played pretty well,” said Penders. “The structure is getting better and it’s a pity that we have lost this game.
“It’s a matter of staying together. I think we’ve had some good games, but after losing these games, we have to stick together.
“It’s the international break now, so we can calm our heads, and when we come back we need to all be motivated and go again.”
The goalkeeper's message is one of collective responsibility rather than allowing frustration to take hold. Chelsea will have time to reflect on their performance during the international window, but Penders wants the players to return with renewed determination and a shared belief in the work being done.
For a side that had enjoyed some positive performances before travelling to Sunderland, the challenge now is to turn those encouraging displays into consistent results.