Hansi Flick labelled Robert Lewandowski the ultimate professional after his second-half winner earned Barcelona a 2-1 triumph over Athletic Bilbao. 

Lewandowski, who spent two seasons under Flick at Bayern Munich, notched his third goal of the new LaLiga season after Oihan Sancet cancelled out Lamine Yamal's deflected opener. 

The Pole netted 83 goals in 71 matches in all competitions between 2019 and 2021, winning eight major titles during Flick's time in charge, which included the Champions League.

And despite turning 36 three days ago, Flick is confident that his star striker can help Barca reclaim their league crown from rivals Real Madrid. 

"I know Robert (Lewandowski) really well and I don't think he has returned to form because that's how I have always seen him as a player," Flick told DAZN.

"I'm happy with him because it's not only the goals he scores, it's his collective effort, the way he dedicates himself to pressing high and very effectively. 

"Physically, he is 100%. He is a total professional, who takes fitness very seriously.

"He knows how to handle pressure and we saw that after the equaliser in the second half. He is a great player."

While Lewandowski received many plaudits for his goal-scoring exploits, Flick was also quick to praise Raphinha for his dynamic display in attacking midfield. 

The Brazilian registered the most touches in the opposition box (nine), with his 19 passes into the final third a total only bettered by Pedri (21). 

He also won more duels (nine) than any other Barcelona player, with Flick believing his versatility will be a huge asset as the season progresses. 

"Rafa can play in any attacking position. He can play as a 10, or he can change positions, he is phenomenal in pressing," Flick said.

"We needed someone like him as we are still missing some players."

Barcelona will look to maintain their unbeaten start to the league season when they travel to Rayo Vallecano on Tuesday before returning to the Nou Camp to take on Real Valladolid next weekend.