Ewa Pajor put Barcelona ahead after eight minutes but Franziska Kett levelled for the Germans midway through the second half.

The Bayern defender went from hero to villain near the end though when she was sent off for pulling the hair of Salma Paralluelo.

Bayern coach Jose Barcala followed shortly afterwards, receiving his marching orders for advancing onto the pitch to protest the decision.

"A tricky situation. She definitely didn't do it on purpose," Bayern's Klara Buehl said of Kett's pull to broadcaster Disney.

"She intended to pull the jersey and for that, she certainly would have deserved a yellow card, no question. But her hair got in the way."

The draw leaves everything to play for in Spain next Sunday, although the Germans will need to beat Barcelona on their home turf without their coach and first-leg goalscorer to reach a first ever final.

Barcelona thumped Bayern 7-1 when these sides met in October, but things were more even this time around in front of 31,000 fans at Munich's Allianz Arena.

Undisputed favourites Barcelona travelled to Munich hoping to qualify for a sixth successive final.

Pinned back from the opening whistle, Bayern countered after seven minutes but Pernille Harder wasted her chance to catch the Catalans out early.

Barcelona punished the hosts immediately when Pajor capitalised on a defensive mistake by Giulia Gwinn and scored a minute later.

Bayern grew into the match and Kett went close to equalising just before the break, forcing a desperation save from Cata Coll.

The visitors went close to doubling their lead on the hour mark when Patricia Guijarro beat the 'keeper but Bayern defender Vanessa Gilles cleared the shot off the line.

Bayern continued to attack and were rewarded for their positivity when Kett struck with 20 minutes remaining.

Buehl charged down the right flank and cut the ball back for Kett to slam home.

Kett then left her team a player short for the final 10 minutes after being shown a straight red card for yanking on Paralluelo's braids.

Barcelona laid siege to the home defence in the dying stages but Bayern held firm to stay in the tie ahead of the return leg.