Toulouse ended Leinster’s 10-match winning streak in the Heineken Champions Cup thanks to Maxime Medard’s 68th-minute breakaway try at Stade Ernest Wallon.

The defending champions’ first European defeat since their April 2017 semi-final loss to Clermont Auvergne saw them get off to a sloppy start. Leinster trailed 14-0 after just 18 minutes and centre Sofiane Guitoune’s third try of the tournament gave Toulouse a 21-13 lead for half-time.

The visitors turned the screw with third quarter tries from James Ryan and Sean Cronin, adding to replacement Sean O’Brien’s 32nd-minute effort and two Jonathan Sexton penalties. However, they were unable to improve their 27-21 advantage, and Louis Madaule’s interception of a Luke McGrath pass sparked a clinical counter attack which ended with Medard’s match winner.

The losing bonus point could yet prove crucial for Leo Cullen’s men, who are only two points behind new Pool 1 leaders Toulouse (eight points) heading into their December double header with third-placed Bath (four points). They visit the Recreation Ground on Saturday, December 8, before hosting the return match at the Aviva Stadium the following Saturday.

Narrow winners at Bath last week, Toulouse tore out of the block in this meeting of the two four-time European Cup champions. Thomas Ramos nailed a tough third-minute penalty after James Lowe was pinged for taking out Cheslin Kolbe. The reliable full-back doubled the hosts’ lead from close range following Florian Verhaeghe’s lineout steal and a strong collective surge up to five metres out.

Leinster’s defence came under further pressure from quick-stepping winger Kolbe and captain Julien Marchand’s lung-bursting run after Jordan Larmour’s offload was picked off by Alban Placines. Toulouse attacked the short side and were rewarded with a 12th minute try as man-of-the-match Medard jinked over in the left corner.

Ramos missed the conversion but was successful with a subsequent penalty for a Leinster offside, with the visitors also forced into a change as O’Brien came on to replace Josh van der Flier (head injury). Some decent phase-building drew a Toulouse offside and skipper Sexton landed the kick from 30 metres out to open Leinster’s account.

The Leinster forwards began to take Toulouse through more phases and a second successful penalty from Sexton, well struck from 40 metres, cut the gap to 14-6. A loose offload spoiled a promising attack, but there was no denying the province just a minute later. Jack Conan’s brilliant footwork and pace saw him burst through the defensive line and he fed the supporting O’Brien to finish. Sexton’s conversion made it a one-point game.

Toulouse had other ideas and a cracking individual try from Guitoune, who evaded the clutches of full-back Larmour after Selevasio Tolofua had done similar to O’Brien, sent them off at the break eight points ahead. Good work from the strong-carrying Lowe got Leinster on the front foot when the second half got underway, and a penalty marched forward 10 metres for dissent saw Sexton kick for the corner.

Toulouse dug deep to defend the lineout maul and a number of pick-and-goes, but second row Ryan showed impressive strength to crash over from a couple of metres out. Sexton’s crisp conversion restored the one-point deficit, but the hosts threatened soon after through the pace of Springbok Kolbe on a kick chase.

It was Robbie Henshaw’s turn to show his kicking skills with a smart grubber through which gobbled up the metres and heaped pressure back on Ugo Mola’s side. Some patient build-up play, coupled with a penalty advantage, led to Cronin charging onto a Sexton pass and he barged through a couple of tackles to make his way in under the posts. Sexton added the extras for a 27-21 turnaround.

Nonetheless, Leinster’s execution and decision-making let them down in their attempts to kick on and sew up a comeback victory. Antoine Dupont added a kicking threat from the home bench and Kolbe continued to be full of energy out wide. A spill just as the navy-clad pack were building from a lineout handed hard-won possession back to the hosts.

The game continued to ebb and flow until replacement Madaule’s intercept outside his own 22 brought the best out of Toulouse’s pacy attack, their well-timed passing and angles of running freeing up Medard to complete his brace. Ramos converted and although he missed a subsequent penalty, Toulouse showed the greater composure as Leinster were left to rue their errors, which included a late lost lineout.

Giving his reaction after the game, Leinster head coach Cullen said: “We were a little too inaccurate at the start and Toulouse built that 14-point lead. I thought we showed pretty good composure and fought our way back into the game.

“Obviously they scored just before half-time but, even at that, I think the lads knew that if they held onto the ball a little bit better and controlled possession that there were going to be opportunities and space out there. 27-21, three tries, we were looking pretty strong at that stage with 55 minutes gone.

“It’s disappointing for us not to push on from there. We have a lineout, they make a good read, come up with an intercept and go the length of the field and it’s those big moments in the game. I thought they did incredibly well in terms of their ability to execute once they make the intercept and the read.

“But from our point of view, there are so many different things in both halves of the game where we cough up positions too cheaply to feed what their strength is – that unstructured, chaotic game and the pace they have out wide. We didn’t put enough of a squeeze on them and, ultimately, that’s what’s cost us but there’s plenty to take out of the game.”