A third goal in three Champions League outings for Wirtz handed Leverkusen the advantage, but Pierre Lees-Melou crashed home a volley to level matters in the first period.

Both sides went into the match with 100 percent records from their two outings so far in the league phase.

They now sit third and fourth in the table on seven points, with Brest ahead on goals scored.

Wirtz, 21, sent the Bundesliga champions into a 24th-minute lead with an arrowed finish from 20 yards.

Wirtz nearly doubled up on 29 minutes but could only muster a tame effort at goal after dancing his way through three defenders on the edge of the box.

But it was Brest who struck next when a looping ball dropped to Lees-Melou on the edge of the box and the midfielder lashed a volley into the bottom corner six minutes before the interval.

Both sides fought for the upper hand in the second half, with Brest surviving desperate Leverkusen appeals for a penalty after the hour when Jonas Hofmann's cross struck a hand but it was adjudged to be in a natural position.

Mahdi Camara then stung Matej Kovar's palms in the Leverkusen goal with a powerful, but too centrally-placed, half-volley with 15 minutes remaining.

Substitute Mama Balde had a golden opportunity on 87 minutes but hit the side netting as he closed in on goal from a tight angle.

Bayer coach Xabi Alonso was left to throw his arms up in frustration as the clock ticked into injury time when VAR again decided not to award his side a penalty after Hofmann was felled in the box.

Wirtz blazed a chance over the crossbar when well positioned inside the box in the 95th minute as Leverkusen sought desperately a late goal that has become a trademark of the side over the last season.

It did not come, however, as both sides were forced to settle for a point.