Corentin Tolisso was left to rue his missed penalty as Lyon fell to a 2-1 defeat in their Champions League third round qualifying first leg against Sparta Prague.

Matej Rynes starred in the second half for Sparta, scoring the leveller before assisting John Mercado's winner either side of Tolisso's skied penalty at epet ARENA on Tuesday.

The hosts thought they took the lead after 20 minutes when Jonatan Braut Brunes managed to find a way past Dominik Greif in the Lyon goal, but the strike was ruled out due to offside in the build-up.

Mercado then squandered a huge chance closer to half-time, inexplicably firing over from six yards out, and Lyon managed to enter the break with a 1-0 lead after Martin Suchomel's attempted tackle on Tolisso sent the ball past his own goalkeeper.

Both sides pushed early on in the second half, with Tolisso forcing a strong save at the near post from Jakub Surovcik before Josimar Alcocer saw a goal disallowed in the 57th minute for offside.

Sparta managed to eventually level just after the hour as Andy Irving's lofted pass into the box was driven low past Greif by Rynes, whose goal triggered an eventful six-minute spell.

At the other end, Lyon debutant Lois Openda won a penalty for the visitors, but Tolisso's spot-kick flew over the crossbar, and Sparta were ahead shortly after as Mercado headed in at the back post from Rynes' cross.

Sparta managed the game well from there on in, restricting Lyon to half-chances while threatening on the counter, and they were able to hold onto their 2-1 lead.

Rynes powers Sparta to victory

It was a deserved victory for Sparta, who produced 1.29 expected goals (xG) to Lyon's 1.28, though the visitors' figure was inflated by Tolisso's penalty.

Sparta created more big chances (three to one) and recorded more touches in the opposition box (23 to 15), while Rynes' determined display from left-back was the catalyst for their second-half turnaround.

Rynes created the joint-most chances for his side (two), completed the most passes in the final third (20), won possession most often (nine) and completed the most final third entries (13) to go along with his goal and assist.

Meanwhile, it was a disappointing debut for Openda, whose only shot in the contest was comfortably saved by Surovcik, though the story could have been different if Tolisso scored the penalty which was won by the Belgian.

The second leg will take place at Groupama Stadium on August 11, with Paulo Fonseca's side now focused on staging a comeback of their own.