Chelsea boss Mauricio Pochettino was delighted after their Carabao Cup penalty shootout win at Newcastle United.
Callum Wilson had Newcastle ahead on 16 minutes, but Mykhaylo Mudryuk found an injury-time equaliser to send the quarterfinal to spotkicks.
Chelsea won the shootout as goalkeeper Djordje Petrovic saved Matt Ritchie's effort after Kieran Trippier had previously fired his penalty wide.
Pochettino said: "I think it was a really good game. We suffered when we conceded, it was our mistake. I said to the players to always believe until the end. Sometimes in football you need some luck and it came. Credit to the players because they were fantastic.
"We were talking before the game that we felt positive after the Sheffield United game. To beat Newcastle, you can see the players on the pitch and it was a good feeling with the fans. It made us really believe, grow and improve. We are doing well, we are recovering players.
"They are so young. It's amazing because we always talk about the talent but being all together helps. We are creating a very good bond. It's about time to know each other. This type of result will help us, but also results like Newcastle away will help us realise what needs to improve."
On reacheing in semi-final, he added: "A very good start. We are so happy. The fans and the club deserve this sort of feeling. It's a big motivation. We are waiting for the draw tomorrow."