Valencia improved after coach Ernesto Valverde made a couple of changes at the break and it was no more than they deserved when centre back Adil Rami surged into the area and volleyed home in the 90th minute.
Wild lungeIbrahimovic was shown a straight red card for a wild lunge on defender Andres Guardado in the second minute of added time but even without the Sweden striker for the return leg in Paris on March 6, PSG will still be favourites to progress.
PSG's latest signing, former England captain David Beckham, watched from the stands and will return to the French capital with the squad on Wednesday for his first training session.
"It is a poor result for us but we have some hope and we will try to turn things around in Paris," Canales told Spanish television broadcaster TVE.
"We knew they would be dangerous going forward but we'll have to see if we can take some of our chances in the second leg. We'll try to go on the attack and score early to get back in the tie. We know it will be tough but we're not going to throw in the towel."