"I've been dreaming of this as a kid" - Maatsen reflects on Dortmund's defeat of Atlético Madrid
Dortmund's marauding full-back was lost for words as Die Schwarzgelben came from behind twice in their two-legged affair to advance to the final four of Europe's premiere competition.
"It's such an amazing feeling. I've been dreaming of this as a kid. Especially now scoring a great goal and [it's] my first goal in the Champions League, so I'm very grateful and so happy. I can't even describe it," Maatsen beamed.
The left-sided defender has enjoyed a stellar last 12 months in his career - winning the English Championship last season with Burnley, and now flourishing with German giants BVB. However, it comes as no shock for the 22-year-old who always had faith in his abilities.
"No, I was surprised you know. I always believed [I would] play for Chelsea as well, but unfortunately for some reasons it didn't work out. But now I'm here [in Dortmund] and I'm very grateful for this opportunity, this moment, and I can say I'm very proud of myself.
"I kept believing in myself and came here [to Dortmund] to experience the highest level and play my game. Tonight I think I showed a very good performance and I'm very happy," he added.
The Netherlands defender also lauded the magic of Dortmund's 'Gelbe Wand', or Yellow Wall. Maatsen believes the bustling 25,000 capacity terrace motivated Edin Terzić’s side over the finish line.
"This Yellow Wall is insane. You felt the energy from the fans and it gives you such a boost. I can't even describe it, you feel it so much in your heart you want to give everything in the tackle, every run, every sprint. It [the atmosphere] goes all through your body and they [BVB fans] are great fans," the 22-year-old said.
Regarding his goal that made it 2-0 (3-2 agg.) on the night, the all-action defender simply reaped the rewards of his hard work in training sessions.
"These opportunities [in front of goal] don't come often for the full back. I was practicing this in training so I took a good touch in the box and put it inside the net as hard as I could. It paid off and it was an amazing feeling," he added.
Maatsen is currently on loan at Borussia Dortmund from his parents club Chelsea. It remains to be seen if BVB will look to buy the electric full-back permanently in summer, but many suspect it will come at a hefty cost given his fine form.