The winger, on loan from Porto, steered the ball into the bottom corner on 74 minutes to register a fourth successive victory for the first time this season.
Yet it was the sublime skill from Kolo Muani, who turned on a sixpence on the edge of the box to elude two markers and then skipped past another two defenders, to set up the Portugal international.
Juve started the contest with a bang, but then were pegged back and outplayed until midway through the first half. After the turnaround the hosts dictated the pace and outshone Inter until the final whistle to record a confidence-boosting victory.
Nicolas Gonzalez tried his luck in the third minute, but then it took another 20 minutes before the hosts got a sniff on goal.
With Inter dominating midfield throughout the first half, by playing five across the middle, the Juventus defence were constantly kept on their toes and at times were left chasing shadows.
Close range attempts from Francesco Acerbi and Lautaro Martinez were blocked on eight minutes, which set the tone for the opening half as Inter steamed forward at every opportunity.
These glaring misses briefly jolted the Bianconeri into life, forcing Yann Sommer to make a trio of saves in the space of 100 seconds to deny Gonzalez, Conceicao and then Muani.
Muani came close to adding to his tally of five Serie A goals on 32 minutes, only for his effort to be deflected inches over the crossbar.
Things got tense before the half-time whistle, with Inter putting Juve under immense pressure without carving out any clear cut scoring chances.
Immediately after the interval defender Renato Veiga and Conceicao both forced a save from Sommer, with the momentum having swung firmly in favour of Juventus.
The Bianconeri were a revitalised unit throughout the second half, which prompted plenty of vocal support from the home fans.
Just before the hour-mark, wayward finishing cost both teams the chance to finally score. Federico Gatti’s header was wide of the target and then Inter’s Henrikh Mkhitaryan miscued his long range shot.
Head coach Thiago Motta welcomed back Andrea Cambiaso from ankle injury, giving the defender just under half-an-hour to get match fit ahead of Tuesday’s Champions League tie at PSV Eindhoven, with Nicolo Savona hauled off.
Inter manager Simone Inzaghi responded with a triple substitution on 62 minutes, as his side were being run ragged since the turnaround. He made two straight swaps in defence and brought on Marcus Thuram for center-back Alessandro Bastoni in a desperate bid to break the deadlock.
Juventus shotstopper Michele Di Gregorio did well to push Thuram's first-time shot onto the post, which resulted in Motta reacting with changes. Conceicao and defensive midfielder Khephren Thuram were replaced late on by teenage forward Kenan Yildiz and Manuel Locatelli respectively.
After Teun Koopmeiners’ missed header, it was Muani’s breathtaking footwork in the box that set up Conceicao for the long overdue goal. The 22-year-old latched onto Muani's pass and coolly picked his spot with a deft left-footer, which went through the legs of outstretched defender Benjamin Parvard and past the diving ‘keeper.
Thuram and Piotr Zielinski wasted chances to equalise. At the other end of the pitch there were late efforts to double the lead. Dumfries made a goal-line clearance to prevent Koopmeiners, Yildiz’s shot was blocked and Sommer denied Muani.
This latest victory, which inflicted Inter's second loss in three matches, earned Juve fans bragging rights over Inter's followers.
While Inzaghi's title chasers are stuttering, in stark contrast Motta's men are on an upward spiral and with a Derby D’Italia triumph will be confidently chasing a fifth win on the bounce when they tackle PSV in the Netherlands on Tuesday.