Golden State Warriors head coach Steve Kerr says his side seemed to take victory for granted after their surprise 129-121 play-off loss to the Los Angeles Clippers.
A Warriors win would have secured a 4-1 series victory and ensured their place in the Western Conference semi-final against the Houston Rockets.
However, they will now travel to Los Angeles for a sixth game.
"We weren't right from the very beginning," Kerr, 53, said.
The Warriors, who lead the best-of-seven series against LA by 3-2, are chasing a fourth NBA title in five seasons.
"We seemed to take it for granted that we were going to be okay. I knew they weren't going to go down without a fight," Kerr added.
"I expected us to come out and play better and win the game."
The Houston Rockets secured their semi-final place with a 100-93 win over the Utah Jazz that sealed a 4-1 series victory.