Borussia Dortmund coach Thomas Tuchel is expecting an improved performance from Porto in the return leg of their round of 32 Europa League tie after seeing his side claim a 2-0 advantage.
Lukasz Piszczek put Dortmund ahead within six minutes at Signal Iduna Park and the victory was completed by a deflected Marco Reus strike with 20 minutes to go.
Porto have a mountain to climb at the Estadio do Dragao in the second leg next week but Tuchel believes the Portuguese outfit will be stronger at home.
"I'm expecting the best Porto in front of their own fans next week," Tuchel said after Dortmund extended their unbeaten run to six matches in all competitions.
"We admit very few scoring chances, have changed a few things in our balance. Today it was very important."
Tuchel praised Turkey international midfielder Nuri Sahin, who shone on his return to action after almost a year out injured.
"We wanted to do a preparation match for Nuri Sahin, but Nuri said he didn't need the friendly match," he added.
"Nuri was awesome, we could no longer restrain him. He has been burning for weeks to play."