Olympique Lyonnais, the team of Van de Sanden, was 2-1 too strong for Bayern Munich (Lineth Beerensteyn) and Arsenal (Vivianne Miedema, Daniëlle van de Donk and Jill Roord) went down with the same numbers against Paris Saint-Germain.
Martens (FC Barcelona) and Janssen (VfL Wolfsburg) already qualified for the semi-finals on Friday.
PSG got the lead against Arsenal after only fifteen minutes of play. Marie-Antoinette Katoto came after a tight corner from Nadia Nadim in front of her opponent and worked the ball into the English goal.
In the Estadio Anoeta in San Sebastián, home of Real Sociedad, Arsenal came just before rest at the same level. Miedema, who, like Van de Donk, had a base place, had trouble making her mark in the attack, but Beth Mead did.
The English international got the ball played in the penalty area, turned away from her opponent and curled the ball beautifully in the far corner.
Both teams were fairly evenly matched during the rest of the game, but in the end it was the PSG that drew the longest end thanks to a goal from Signe Bruun.
After weakly defending Katie McCabe, Katoto picked up the ball and delivered it to Bruun who only had to put her foot against the ball.
Lyon struggling along Bayern
Olympique Lyonnais, for years the leading club in the Champions League, had a lot of trouble at the San Mamés in Bilbao. With Shanice van de Sanden on the bench, the tournament winner of the past four seasons had a hard time making a fist.
But the German team, where Lineth Beerensteyn had a base place, had to capitulate just before the break. A high ball from Eugénie Le Sommer fell behind the Bayern defence and Nikita Parris was there like chickens to head the ball past keeper Laura Benkhart. The two were hard hit, but Parris was able to go on.
Amel Majri seemed to lock up the game by making it 2-0 after just under an hour of free kick, but not much later Carolin Simon brought the excitement back into the game. The German saw her low free kick without being touched in the goal.
But it turned out to be a small revival because Bayern insisted on the rest of the duel, but a dangerous final offensive did not come.
PSG and Lyon face each other on Wednesday in the semifinals, FC Barcelona and VfL Wolfsburg meet each other in the other semifinals. The final of the Champions League is scheduled for next Sunday.