The Bianconeri have one foot in the Champions League proper after thrashing Artmedia Petrzalka 4-0 and will be firm favourites to complete the task when they travel to Slovakia on August 26.

However, Ranieri is not taking anything for granted.

"There's a return match too," he told Juventus Channel. "We'll have to stay very concentrated there, keeping in mind that this team won 5-0 against Celtic (three) years ago.

"But we're obviously in a good position to go through and in two weeks' time we'll be even fitter.

"We always bossed the game; on the whole it was a good performance."

Pleased to be back in Europe after a two-year absence, Juventus were on the attack from the off. Mauro Camoranesi opened the scoring after just seven minutes and Alessandro Del Piero made it two shortly before the half-hour mark.

Giorgio Chiellini added a third to all but settle the tie before half-time before Nicola Legrottaglie completed the rout in stoppage time.

Aside from his goal, Del Piero put in a man-of-the-match performance as the Juve captain led by example.

While delighted to be back in Europe, Del Piero joined his manager in warning his team-mates against complacency.

"We played a good game, we weren't lacking in almost anything," said the veteran striker. "We created several chances and didn't risk much at the back.

"We're satisfied, but we mustn't think too much about this result, we must keep going. We need to focus immediately on the return game.

"Four goals can be enough to go through, but only if we play the return match with the same intensity and determination."