Toulon replacement Jonny Wilkinson missed two late penalties as Toulouse completed a comeback from 0-12 down to win 13-12.
Frederic Michalak kicked four penalties in the first half as the European champions benefited from the considerable wind behind their backs at the Stade Ernest-Wallon.
But a try from South African international Jano Vermaak in the second period swung the result in Toulouse's favour, as they saw-off a Toulon outfit that were missing several leading names including Bakkies Botha and Matt Giteau.
The home side lost France number eight Louis Picamoles to injury within the first ten minutes, introducing the monstrous Gillian Galan off the bench following his starring role against Saracens in the Heineken Cup.
Michalak struck his first penalty in the 11th minute, before good work at the breakdown brought three more points for Toulon.
Vermaak's slow distribution of the ball into a scrum won Toulon another penalty a few minutes later, with the former Toulouse star Michalak converting to give the visitors a 9-0 lead after 23 minutes.
A yellow card given to Toulouse fly-half Jean Pascal Barraque for unsportsmanlike conduct compounded the home side's woes, as Michalak's fourth strike stretched the gap to 12.
With Barraque off the field, Vermaak filled in on kicking duties for Toulouse but missed a penalty attempt as they sought to grab a foothold in the game, a feat not made any easier thanks to Toulon's dominant pack.
The visiting set of forwards created a drop goal opportunity for Michalak just before the interval, but the ball faded to the left of the posts. It meant that after Florian Fritz missed a long-range attempt for Toulouse just before the break, Toulon lead 12-0 at half-time.
Barraque, back on the field, finally handed Toulouse some points in the 45th minute with a long-range penalty before a missing a second attempt five minutes later.
With the wind at their backs though Toulouse were a greater force and Toulon conceded a run of penalties, ending in a yellow card for Andrew Sheridan.
Toulouse's superior scrum began to dictate as Jean-Marc Doussain, a replacement for Barraque, added one penalty and missed another before the hosts eventually took the lead.
Vermaak's try set up by Joe Tekori saw Toulouse cancel out Toulon's comfortable half-time advantage to surge iinto the lead on the 70th minute to the delight of the home fans.
Toulon had one card left to play and brought on Jonny Wilkinson, but the former England fly-half missed a penalty opportunity in the 73rd minute. A second miss a few minutes later, regardless of the tricky wind, cost his side for good as Toulouse moved top of the league and three points clear of their closest rivals and Montpellier.
Pens: Barraque, Doussain
Yellow Cards: Barraque
Pens: Michalak 4
Yellow Cards: Sheridan
Toulouse: 15 Maxime Medard, 14 Yoann Huget, 13 Florian Fritz (c), 12 Gael Fickou, 11 Hosea Gear, 10 Jean-Pascal Barraque, 9 Jano Vermaak, 8 Louis Picamoles, 7 Thierry Dusautoir, 6 Gregory Lamboley, 5 Patricio Albacete, 4 Romain Millo-Chluski, 3 Census Johnston, 2 Christopher Tolofua, 1 Gurthro Steenkamp.
Replacements: 16 Chiliboy Ralepelle, 17 Schalk Ferreira, 18 Yohan Montes, 19 Yannick Nyanga, 20 Joe Tekori, 21 Jean-Marc Doussain, 22 Clement Poitrenaud, 23 Gillian Galan.
Toulon: 15 Drew Mitchell, 14 Alexis Palisson, 13 Mathieu Bastareaud, 12 Rudi Wulf, 11 David Smith, 10 Frederic Michalak, 9 Sebastian Tillous-Borde (c), 8 Juan Smith, 7 Pierrick Gunther, 6 Virgile Bruni, 5 Jocelino Suta, 4 Konstantin Mikautadze, 3 Martin Castrogiovanni, 2 Craig Burden, 1 Andrew Sheridan.
Replacements: 16 Jean-Charles Orioli, 17 Florian Fresia, 18 Joe Van Niekerk, 19 Chris Masoe, 20 Juan Martin Fernandez Lobbe, 21 Delon Armitage, 22 Maxime Mermoz, 23 Carl Hayman.
Referee: Alexandre Ruiz