Barcelona took a "giant step" towards a successful season with a thrilling comeback win over Granada, Ronald Koeman said.
The Catalans claimed a remarkable 5-3 Copa del Rey quarter-final win on Wednesday after forcing extra time at Estadio Nuevo Los Carmenes.
Barca were trailing 2-0 as late as the 87th minute only for Antoine Griezmann and Jordi Alba to force the additional period, after Francisco Trincao, Lionel Messi and Ousmane Dembele had all hit the woodwork.
Griezmann made it 3-2 only for a Fede Vico penalty to level matters again, but Frenkie de Jong scored from a rebound and Alba smashed home a stunning volley to secure Barca's semi-final spot.
Koeman last week suggested his side were not ready to compete for the biggest trophies and the Barca boss remains unconvinced they could end 2020-21 winning LaLiga, the Copa and the Champions League.
However, he believes their fightback against Diego Martinez's side could perhaps be a turning point in their campaign.
He said: "I was referring to winning the three trophies: LaLiga, the Champions League and the Copa. I don't believe [we can win all three]. But I've always believed in the team. We've improved many things, above all in character. We've taken a giant step forward.
"It helps to have spirit and strength in the team. That's the way. We've worked a lot to get to the moment when the team starts to believe and it's a proud feeling. And it's come at an important moment of the season.
"We started the game really strongly, we played really well in the first 20 minutes. A mistake in playing where we shouldn't be playing cost us a goal.
"You have to highlight the team's mentality because we never gave up. We had really bad luck with the woodwork. We did everything to win the game.
"We deserved it due to the mentality of the team, but on this occasion, we showed we know how to suffer. We knew how to defend the result and we deserved the win."
Griezmann proved pivotal to the result, scoring Barca's first before setting up Alba's equaliser with a cushioned header from a Messi cross.
The France star then converted an emphatic header of his own and teed up Alba's spectacular second with a clever outside-of-the-foot pass.
It was the first time the €120million man had been directly involved in four goals in the same game for the Catalans.
"I'm really pleased with Griezmann," said Koeman. "I know it's really important for him. The team needs him. With his effectiveness, we're more dangerous."