Paris - Lyon reached the French Top 14 semi-finals for the first time on Friday despite drawing 19-19 with favourites Toulon, advancing courtesy of scoring two tries to their opponents' one.
The extra-time win against the three-time European champions gave Lyon a semi-final clash against Montpellier next weekend.
Toulon led 13-6 and then 19-16 in extra-time before New Zealand-born Australian international flyhalf Mike Harris booted his third penalty of the match seven minutes from the end to secure the draw and victory.
"To come here to the Stade Mayol and win, it's incredible," said Lyon coach Pierre Mignoni whose side were only promoted to the top flight two years ago.
"I said to the players that we had everything to win even if journalists said we had nothing to lose."
Lyon had lost 39-11 to Toulon on the same ground in the regular season in December, an occasion that Mignon described as his team being "in a hole".
"We were on a run of defeats then after a good start to the season but I always knew we'd qualify (for the play-offs).
"We could have sunk but the lads all worked very hard."
Toulon skipper Mathieu Bastareaud was left heartbroken after another fruitless season for the big-spending club whose last Top 14 title came in 2014.
They were runners-up in the last two seasons while this year's European Champions Cup campaign ended in a quarter-final loss to Munster.
"It's a huge disappointment, it's sad and very frustrating," said the French centre.
"We had lots of chances but couldn't take them. It's a bad season. The club has ambitions to win titles but again we have won nothing."
Toulon, bidding for a seventh successive appearance in the semi-finals, trailed 6-3 at the end of the first half after Harris and Anthony Belleau traded penalties.
But they eventually stormed into the lead thanks to a try from English winger Chris Ashton after 56 minutes with Belleau adding the extras.
Lyon stormed back with fullback Toby Arnold and flanker Dylan Cretin scoring what proved to be the crucial tries.
Francois Trinh-Duc had kicked a penalty for Toulon for 16-11 before Cretin's score.
Trinh-Duc then made it 19-16 in extra-time before Harris's decisive kick to level the scores on the night with Lyon taking territorial advantage of Toulon reduced to 14 men following a yellow card for All Blacks icon Ma'a Nonu.