Juve enjoyed a narrow 1-0 win over Fiorentina in Serie A on Sunday to maintain their title charge and it looked as though it would be a case of deja vu for Vincenzo Montella and his men on Thursday after Arturo Vidal's early opener in the first leg.
Hosts Juve, unbeaten at home in all competitions since April 10, made the ideal start when Vidal scored for a second successive Europa League game after just three minutes.
Both sides had plenty of goalscoring opportunities after that, but it looked as though Juve's defence would keep a clean sheet for a sixth straight game in all competitions.
However, substitute Gomez, who returned to action in mid-February after suffering a long-term knee injury in September, chose the ideal time to get on the scoresheet again with 11 minutes remaining as he gained Fiorentina a potentially vital away goal heading into next week's second leg.
In what was a strong start, Juve needed less than three minutes to open the scoring, Vidal firing home from close range after Sebastian Giovinco had done well to chest Claudio Marchisio's powerful cross into his path.
Vidal was in the thick of it again soon after when he flashed an effort wide from distance as Antonio Conte's men made all of the early running.
Stefan Savic was forced to clear Kwadwo Asamoah's pacy delivery from a dangerous position before Alessandro Matri had Fiorentina's first chance - diverting Alberto Aquilani's effort wide of Gianluigi Buffon's right-hand post.
That sparked a short spell of pressure from Montella's men - Matias Fernandez forcing Buffon into a smart save with Asamoah required to acrobatically clear the rebound before the onrushing Borja Valero could follow up.
Vidal threatened twice more late in the half - both with headed efforts - seeing the first saved by Neto before the crossbar denied him seven minutes from the interval.
Juve were given a scare early on after the restart when Valero dispossessed Angelo Ogbonna in possession and found himself through on goal, before referee Bjorn Kuipers brought play back for a foul on the defender.
With Juve keen to avoid conceding an away goal and Fiorentina eager not to fall further behind in the tie, the tempo dropped somewhat and chances became scarce.
However, Gomez needed only one sight of goal when, after being involved for just 12 minutes, he trapped a long ball well and slipped the equaliser past the onrushing Buffon.
