Milos Krasic and Simone Pepe beat Catania 2-0, but as Juventus welcome back Gigi Buffon, they lose Luca Toni to injury.
The goalkeeper hadn't played an official match since the 2010 World Cup tie against Paraguay on June 14, as back surgery kept him out for seven months. Alessandro Del Piero also returned after his controversial benching against Napoli to partner new arrival Toni.
Catania had the first chance after four minutes when a corner was not cleared and the Gennaro Delvecchio free header was over the bar.
Bad news for Juve in the opening minutes, as Toni limped off with a suspected sprained right knee after falling awkwardly under a Nicolas Spolli aerial challenge. With no other strikers available, Alberto Aquilani came on and Pepe pushed up to a forward position.
Buffon needed his wits about him to rush off the line and clear from both Martinho and Mirko Antenucci. Andrea Campagnaro was in a similar situation confronted by Krasic and Aquilani.
The deadlock was broken out of nowhere at the 35th minute. Del Piero shook off Blazej Augustyn with a couple of dummies to chip in a cross practically from the by-line, finding Krasic for a brilliant angled volley at the back post.
It should've been 2-0 with another inspired Del Piero pass, flicking it over the defence without even looking to send Claudio Marchisio clear, but the first touch let him down when he only had the goalkeeper to beat.
Pepe doubled the Juventus tally after the restart. Del Piero's corner was knocked on by Giorgio Chiellini for the makeshift striker to tap in at the back post.
They thought it was 3-0 when Del Piero redirected a Pepe cross-shot, but he had strayed offside.
Catania should've pulled one back 10 minutes from time, but Delvecchio ballooned over Adrian Ricchiuti's assist from seven yards.
In the final stages Buffon needed a very tough save, at full stretch to fingertip the deflected Simone Pesce strike round the post. From the resulting corner, Augustyn's shot was deflected over by Leonardo Bonucci's sliding tackle.
In stoppages Del Piero was given a standing ovation by the crowd and handed the captain's armband to Buffon.
Juventus go on to face either Roma or Lazio in the quarter-finals.
Juventus 2-0 Catania
Scorers: Krasic 35 (J), Pepe 54 (J)
Juventus: Buffon; Sorensen, Bonucci, Chiellini, Grosso (Grygera 46); Krasic, Melo, Marchisio, Pepe; Del Piero (Motta 90), Toni (Aquilani 18)
Catania: Campagnolo; Silvestre, Augustyn, Spolli (Strumbo 90), Marchese; Sciacca, Martinho (Pesce 76), Delvecchio; Mascara (Gomez 73), Ricchiuti; Antenucci
Think you know your Italian football? Share your knowledge, tips and comments to win cash prizes in OLBG's tipster competition - £5,000 monthly.