Ronaldo scored from 12 yards nine minutes after the break when strike partner Paulo Dybala won a penalty. Francesco Caputo had given Empoli a first-half lead. Juve's record signing rocketed in a fierce shot in the 70th minute as the Bianconeri made it nine wins from 10 in the league to start the season.
Dybala Brings Out the Best in Ronaldo
As good as Ronaldo is, he's at his best when Dybala is alongside him in the lineup. The Argentina international scored Juve's winner over Manchester United in the UEFA Champions League on Tuesday after good work from Ronaldo.
The same combination proved the undoing of the Empoli defence when Dybala was hauled over by former Arsenal midfielder Ismael Bennacer early in the second half. Ronaldo made no mistake from the spot.
He also benefited considerably from Dybala's varied and perceptive range of movement. The South American is not a traditional centre-forward, and his penchant for dropping off the front leaves room in the middle for Ronaldo's trademark runs from out to in.
Dybala's willingness to vacate central areas adds fluidity to the Juve forward line by granting Ronaldo the freedom to roam off the left. The latter's second goal was a prime example, with Dybala taking his place on the left while Ronaldo drifted to the right of centre before receiving a pass from Blaise Matuidi and thundering in an unforgettable strike.
Unlike some other members of the Juventus forward line, Dybala complements Ronaldo brilliantly. The duo can fire the Bianconeri to another Serie A title as well as glory in the Champions League.
Federico Bernardeschi Is the Wrong Fit Alongside Ronaldo
Ronaldo was subdued for most of the opening 45 minutes, as he toiled in a front three not completely complementary to his particular skills. Specifically, the inclusion of former Fiorentina wide forward Federico Bernardeschi didn't bring the best out of Juve's prolific No. 7.
Bernardeschi's game is based on timely runs in behind from out to in. Those are the same runs Ronaldo relies on, with Ronaldo more effective with a target man alongside him who will do the dirty work.
Mario Mandzukic usually fills the latter role, but he missed his second game running with an ankle problem. Ronaldo didn't score without Mandzukic in the team when Juventus beat Manchester United 1-0 at Old Trafford on Tuesday.
He's missing Mandzukic's ability to hold the ball up and win aerial duels to release him with clever flicks and knock-downs. By contrast, Bernardeschi wants to play pass-and-move football, spin in behind and occupy similar pockets of space to those Ronaldo favours.
The similarities in their games were summed up when the pair went for the same chance in the first half:
Bernardeschi struggled to trouble the Empoli defence with his movement. The 24-year-old also struggled to find his passing range and was clumsy out of possession, drawing a yellow card for a rash challenge two minutes before the break.
It was fitting Ronaldo's first goal didn't come from open play. More fitting still was that his second goal came after Bernardeschi had been subbed for Juan Cuadrado.
Bernardeschi is a wide player who loves to drift centrally, much in the mold of Ronaldo. Playing both together makes the Juve attack predictable, a lesson the Serie A leaders learned the hard way in Empoli, particularly during the first half.
Daniele Rugani Is Not the Future of the Juve Defence
On Friday, Juve manager Massimiliano Allegri heaped praise on Daniele Rugani:
The former Empoli man was in a position to justify those words when he replaced Giorgio Chiellini, who withdrew prior to kick-off:
Instead, all Rugani proved is that he's anything but the future of the Juventus defence. The 24-year-old was a bag of nerves, as he lacked the assurance and aggression Chiellini brings to the back line.
Rugani was bullied off the ball too easily in the buildup to the opening goal and struggled to stay with Caputo's movement for most of the game. Awareness of space around him and timing in his tackles also appeared to desert Rugani.
As an audition for the role of talisman-in-waiting when the 34-year-old Chiellini and 37-year-old Andrea Barzagli eventually call time on their Juve careers, Rugani's performance was far from convincing.