Juventus, the most successful side in the competition's history with 15 trophies, host Empoli in the next round, while Cagliari will return their focus to the Serie A relegation battle.
Vlahovic, the focus of Juventus supporters' anger after Saturday's 2-2 draw with Venezia, soaked up the applause this time, scoring a minute before the break on Tuesday night.
Koopmeiners added a second direct from a free kick eight minutes into the second half, Conceicao netted 10 minutes from time before Gonzalez wrapped up the win in the 89th minute.
Serbian striker Dusan Vlahovic slams home Juve's opener in Turin. (AP PHOTO)
Cagliari were quickest out of the blocks with Gianluca Lapadula forcing Juve keeper Michele Di Gregorio into a point-blank save in the opening minute, but after that it was the home side who took control.
Vlahovic fired over from a tight angle at the edge of the six-yard box before Kenan Yildiz had an acrobatic volley blocked by defender Mateusz Wieteska.
Conceicao then curled a shot just wide of the far post from outside the area and he had a similar effort on target minutes later which Cagliari keeper Simone Scuffet denied with a diving save.
Cagliari almost held out until halftime, but when Vlahovic received a pass from Yildiz in the box with his back to goal, he controlled the ball and turned and struck his effort through the legs of Wieteska and in off the far post.
Juventus doubled their lead when Koopmeiners whipped his free kick from well outside the area over the wall and into the top corner, and had little trouble seeing out the win.
Teun 🔛 target 🎯— JuventusFC 🇬🇧🇺🇸 (@juventusfcen) #JuveCagliari [2-0] #CoppaItaliaFrecciarossa pic.twitter.com/2FsGdRgfJKDecember 17, 2024
Vlahovic twice had the ball in the net in the second half, both ruled out for offside but Conceicao finally got the goal his performance deserved, cutting inside from the right and bending his finish into the far bottom corner.
Substitute Gonzalez went on a solo run before lobbing the keeper as Juventus, who have drawn their last four league games, continue to enjoy success in cup competitions having also beaten Manchester City in the Champions League last week.
