The hosts looked to be heading for a narrow defeat in their opening UEFA Champions League Group E clash after Pablo Barrios fired the visitors into a 29th-minute lead.
But under instructions to go up for a corner in the fifth minute of added time, Provedel continued to loiter in the box before leaping to glance a Luis Alberto cross past his opposite number Ivo Grbic.
Provedel’s goal was the sixth by a goalkeeper in the Champions League and only the second from open play, after Sinan Bolat scored for Standard Liege against AZ Alkmaar in 2009.
There was also drama in the other Group E encounter as goals from Calvin Stengs and Alireza Jahanbaksh saw Feyenoord claim a 2-0 win over Celtic, who finished the game with nine men.
Stengs’ free-kick snuck home to give the Dutch side the lead on the stroke of half-time and Brendan Rodgers’ men unravelled after the interval as both Gustaf Lagerbielke and Odin Thiago Holm saw red.
Julian Alvarez came to the rescue for holders Manchester City, who survived a major scare before seeing off Red Star Belgrade 3-1 at the Etihad Stadium.
Osman Bukari fired the visitors in front against the run of play just before half-time but it took Alvarez 72 seconds of the second half to slide his side back in front.
Alvarez had a say in City’s second as his free-kick was flapped into his own net by Red Star keeper Omri Glazer, and Pep Guardiola’s men wrapped up a deserved victory when Rodri produced a typically composed finish 17 minutes from time.
Also in Group G, substitute Benjamin Sesko scored in injury time to seal a 3-1 win for RB Leipzig at Young Boys.
Joao Felix shone with two goals and an assist as Barcelona proved far too strong for Royal Antwerp, cantering to a 5-0 home victory in Group H.
The Portugal international fired an 11th-minute opener before Robert Lewandowski added his side’s second on 19 minutes for Xavi’s in-form side.
The visitors, returning to the top level of European football for the first time in 65 years, fell further behind after 22 minutes when Jelle Bataille’s unfortunate deflection flew in off the post.
Barca were in cruise control with teenager Gavi adding his side’s fourth goal nine minutes into the second half before the outstanding Felix deservedly completed the rout with his second just past the hour mark.
Two goals from Galeno helped Porto begin their Group H campaign with a 3-1 win over Shakhtar Donetsk in Hamburg.
Kylian Mbappe opened the scoring from the penalty spot as Paris St Germain kicked off their Group F campaign with a 2-0 win over Borussia Dortmund.
The hosts had to wait until the 49th minute for their opener but made sure of the points in the 56th minute when Achraf Hakimi doubled their advantage with a quality finish.
Rafael Leao missed a golden chance to kick AC Milan’s Group F campaign off with a win against Newcastle at the San Siro.
The Portugal international had only keeper Nick Pope to beat after a surging 34th-minute run but attempted an audacious flick and only succeeded in tripping himself.
Pope made a series of fine first-half saves to earn a point for the Magpies in their first top-level European match for 20 years, but the frustration was clear among the fans of the seven-time winners.