After extra time saw the Fifth Round tie finish 1-1, Newcastle keeper Martin Dubravka saved two penalties in the shootout, with Harvey Barnes missing his spotkick for Newcastle.
Eustace later said: "I am extremely proud of the players. It was a group effort. If we are going to be successful at anything we do this year it is about the squad of players.
Advertisement
Advertisement
"That was our sixth game in 18 days so the squad was important tonight and everyone was at it.
"We are improving with every game we played and that was probably the best we played with the ball.
"I am also really proud of the supporters. It was a real club effort tonight.
"I have no problems with anyone missing penalties, I am proud of them for stepping up."