Clermont came back from 0-19 down in the second-half to run out 24-19 winners against Bordeaux-Bègles at Stade Chaban Delmas on Sunday.
Play-off hopefuls UBB looked set to pick up the four points after carding four Pierre Bernard penalties and a converted Berend Botha try by the 44 minute mark, with Clermont unable to trouble the scorers in a poor first-half showing.
But then came a dramatic closing half-hour as the Top 14 pace-setters clicked into gear with tries from Alivereti Raka, Patricio Fernandez and Wesley Fofana ultimately seeing them stun the home crowd and seal an unlikely victory.
Clermont are now five points clear of Toulon in the standings after this win, with Bordeaux-Bègles remaining in fifth position as they wonder what might have been after letting that hefty 19-point advantage slip through their fingers.
Pen: Bernard 4
Tries: Raka, Fernandez, Fofana
Con: Fernandez 2, Parra
Bordeaux-Bègles: 15 Jean-Marcelin Buttin, 14 Metuisela Talebula Maijaina, 13 Adam Ashley-Cooper, 12 Julien Rey, 11 Blair Connor, 10 Pierre Bernard, 9 Baptiste Serin, 8 Peter Saili, 7 Luke Braid, 6 Louis-Benoit Madaule, 5 Berend Botha, 4 Julien Ledevedec, 3 Sekope Kepu, 2 Ole Avei, 1 Jefferson Poirot
Replacements: 16 Benat Auzqui, 17 Steven Kitshoff, 18 Cyril Cazeaux, 19 Hugh Chalmers, 20 Loann Goujon, 21 Yann Lesgourgues, 22 Jean-Baptiste Dubie, 23 Jean-Baptiste Poux
Clermont: 15 Scott Spedding, 14 Hosea Gear, 13 Jonathan Davies, 12 Wesley Fofana, 11 Alivereti Raka, 10 Patricio Fernandez, 9 Ludovic Radosavljevic, 8 Damien Chouly, 7 Judicael Cancoriet, 6 Camille Gerondeau, 5 Sebastien Vahaamahina, 4 Paul Jedrasiak, 3 Clement Ric, 2 John Ulugia, 1 Thomas Domingo
Replacements: 16 Pellow van der Westhuizen, 17 Raphael Chaume, 18 Arthur Iturria, 19 Peceli Yato, 20 Morgan Parra, 21 Brock James, 22 Isaia Toeava, 23 Dan Kotze
Referee: Romain Poite