Juergen Klopp was relieved to avoid an upset against Wilhelmshaven as Borussia Dortmund booked their spot in the DFB-Pokal second round.
Last season's Bundesliga runners-up eventually progressed 3-0 against the fourth-tier side at the Jadestadion on Saturday, but they were made to work hard for victory.
Aaron Siegl in the Wilhelmshaven goal was particularly impressive as he kept out first-half efforts from Marco Reus, Robert Lewandowski, Nuri Sahin and Pierre Emerick-Aubameyang.
But the away side's pressure finally paid dividends in the second half, as first right-back Kevin Grosskreutz drilled home from the edge of the area in the 71st minute before Marvin Ducksch added a second from six yards after excellent work from Jonas Hofmann and Lewandowski added gloss to the scoreline in injury time.
Klopp was quick to pay tribute to the underdogs, admitting that his side had been given a tough workout.
"A big compliment to Farat Toku and his team, they've done really well," he told the club's official website.
"We have not played an outstanding game, but if the goalkeeper of Wilhelmshaven hadn't had one of his best days, we could have decided things earlier.
"We can improve how we convert our chances, but we have scored three nice goals, had shots and deserve to move into the next round. I have no major concerns."
Wilhelmshaven manager Toku admitted that Dortmund looked good ahead of the start of the new Bundesliga season - although he was pleased with the efforts of his own side.
"It's not easy to put pressure on a Champions League finalist," he added. "But we managed that. We managed to close the spaces.
"When we managed to hold them to 0-0 at the break, we already wanted to celebrate."
|Coach: F. Toku|
for D. Loheider 58'
for D. Jahdadic 69'
for Y. Buduar 74'
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