By Simon Lewis Thomond Park
Key moment: Conor Murray's opportune try on 28 minutes was a real momentum shifter, sending Munster into the interval with a slender 10-6 lead after Toulon had looked ominous in the opening quarter but Andrew Conway's 75th-minute try was the real turning point as Munster looked to have blown their last chance, the wing's brilliant piece of individual skill, pace and grace under pressure providing the try that finally turned the game Munster's way in a real nail-biter.
Talking point: Munster are into yet another European semi-final and it took the performances of this young team's lives to do so, overcoming a heavyweight Toulon side in all senses of the word, unheralded Irish pros defeating a team of household names in a testament to brilliant preparation and collective spirit.
Key man: If ever Munster needed a captain's performance from Peter O'Mahony it was today and the Corkman duly delivered, carrying and leading from the front and a colossus at the lineout.
Munster had plenty of heroes at Thomond Park, particularly amongst a makeshift backline hit by injuries but O'Mahony's display was pure grit.
Ref watch: Nigel Owens contributed to the drama with a lengthy deliberation in conjunction with TMO and fellow Welshman Jon Mason over whether to award Munster's first-half try, as Conor Murray took advantage of Toulon lethargy to nip in from an onside position and claim a loose ball that had come out of a ruck on the French tryline.
It took an age to reach a decision as the agitated home crowd grew impatient, before eventually raising his arm to award the try and contributed to an opening half that lasted way beyond 50 minutes.
The drama continued as Owens clamped down on Munster's rucking in the second half but he will be forgiven after blowing up Chris Ashton at the death as Toulon threatened a smash and grab past 80 minutes.
Penalties conceded: Munster 9 Toulon 6
Injuries: Simon Zebo had been a doubt all week with a hamstring injury and his game was effectively over inside the first minute as he collided with Chris Ashton in averting a Toulon try.
Zebo would play on for another 24 minutes before limping out.
Munster will also have a concern over Conor Murray, who played for 77 minutes but seemed to hobble out of the game.
Next up: Munster can plan for a Champions Cup semi-final in France on the weekend of April 21/22 against the winners of Clermont and Racing 92, who play their quarter-final on Sunday.
If Clermont win, then it's off to Saint-Etienne but if Racing win away, then Bordeaux will be the host city.
Andrew Conway took on the mantle of matchwinner for Munster as his stunning 74th-minute try saw them pip Toulon 20-19 in a titanic European Champions Cup quarter-final at Thomond Park.
Winger Conway's decisive score from a kick return, which saw him beat four defenders from near halfway, sent the Irish province through to a record 13th European semi-final and a trip to France to face either Clermont Auvergne or Racing 92.
Replacement Francois Trinh-Duc almost inspired a famous Limerick victory for Toulon, kicking two penalties and having a key involvement in Chris Ashton's converted try as the three-time champions began the final quarter with 13 points in little over seven minutes.
However, Munster - who led 10-6 at half-time thanks to an opportunist Conor Murray try near the half hour mark - used all of their cup nous to pull off a gritty comeback triumph thanks to Conway's dazzling effort and Ian Keatley's all-important conversion.
Toulon's threat was obvious right from the first minute, fortune favouring Munster as Simon Zebo did just enough to prevent Ashton from scoring off Eric Escande's dangerous kick. Not for the first time, the hosts rode their luck in avoiding a possible penalty try.
Peter O'Mahony's lineout steal, coupled with Conway's vital tackle on Josua Tuisova on the opposite wing, kept the visitors scoreless until Anthony Belleau, a late inclusion at fly-half for Trinh-Duc, fired over a well-struck 10th-minute penalty.
After Munster turned down a long-range kick, CJ Stander was squeezed out in the left corner and the covering Ashton beat Conway to a Simon Zebo kick through.
Raphael Lakafia's hoovering up of Billy Holland's lineout steal allowed the beefy Toulon pack to get within range for Belleau to score an 18th-minute drop goal for a 6-0 lead.
The injury-enforced withdrawal of Zebo robbed Munster of one of their key attackers but a couple of frenzied kick chases, allied to a strong carry from Jack O'Donoghue, led to Murray's momentum-changing 27th-minute score. Toulon thought they had covered the danger, only for France captain Guilhem Guirado to knock on at a ruck close to his own line and Murray pounced to ground the ball.
A prolonged deliberation between referee Nigel Owens and TMO Jonathan Mason went Munster's way, and Keatley converted and then tagged on a 31st-minute penalty, punishing Semi Radradra for tackling replacement Darren Sweetnam without the ball.
Murray was short and wide with a penalty attempt just inside the Toulon half, before the French powerhouses got no reward again from a Dave Attwood break and a threatening late attack that saw Sam Arnold bump Ma'a Nonu into touch.
Defences were on top in the early stages of the second period, Munster getting on the front foot with O'Mahony continuing to cause problems for the Toulon lineout. The excellent Arnold hauled down Tuisova as he threatened from deep, while the consistently well-positioned Ashton covered Sweetnam's chip-and-chase effort.
Munster's front row reserves came up trumps in winning a scrum penalty which Keatley turned into three points, but Toulon's own bench proved hugely influential entering the final quarter.
Radradra just lost control of the ball as he stretched for the line, under pressure from Alex Wootton, before Trinh-Duc punished Jean Kleyn's side entry at a maul to cut the gap to 13-9.
It got even better for the travelling support when Trinh-Duc's offload near halfway was adjudged to be flat, releasing Mathieu Bastareaud who charged through and put the supporting Ashton diving in under the posts. Suddenly, Toulon had a grip on proceedings as Trinh-Duc's pinpoint 48-metre penalty, won by Tuisova, gave them a 19-13 advantage.
It was all hands to the pump for Johann van Graan's injury-hit side, replacement Niall Scannell being held up by Bastareaud before Munster's decision to go wide was foiled by the Toulon rearguard.
Conway came to Munster's rescue, brilliantly keeping a Trinh-Duc clearance in play and, with Tuisova having run infield, the Ireland international expertly slalomed his way through the cover to cross close to the posts. Keatley added the extras and Munster's defence did the rest, frustrating Toulon into submission.