Klopp delighted with 'perfect day'
Norwich City manager Chris Hughton believes his team need to do more to guarantee themselves a spot in the English Premier League.
The win saw Dortmund book their place in next season's Champions League and they came through unscathed as they prepare for their clash against Real Madrid on Wednesday.
Klopp's side were below their best but goals from Marco Reus and Robert Lewandowski secured a straightforward win for the hosts at Signal Iduna Park.
"We have rarely found the game as easy as we have today," Klopp told the club's website.
"Our first attack brought us the lead and for the next 20 or 25 minutes, we were really great.
"Then we lost our way a bit and Mainz were somewhat stronger. We were lucky that they did not equalise but we have experienced games like this before so we adjusted a bit during the break and then played an intense second half to win the game.
"Also, nobody got injured, so it's been a perfect day for us."
Defender Marcel Schmelzer was just as happy with the win because it ensured Dortmund will be in the Champions League next season, irrespective of the outcome of their semi-final showdown with Real Madrid.
"Yes, that is very important," he told RuhrNachrichten.de. "We have always stressed that this was our primary goal for the season.
"Also, now we don't have to read questions about how we're supposed to beat Madrid when we cannot even focus properly on the league.
"It was always very important to us that we focused fully on the game immediately in front of us, and we managed that today."