The victory - the biggest ever in this competition by a fourth-tier side against top-flight opposition - was as good as sealed by the interval as the hosts quickly moved into a 3-0 lead.
Metin Cakmak opened the scoring after two minutes before AK doubled their advantage after half an hour when Justin Gerlach slotted home.
Kevin Kruschke made it 3-0 to leave Markus Babbel's visitors reeling.
Cakmak's second of the match completed an amazing rout as Hoffenheim failed to find any response after the break.
There were no such problems for reigning Bundesliga champions and current DFB-Pokal holders Borussia Dortmund, who were comfortable 3-0 winners over Oberneuland.
Marco Reus opened the scoring after 10 minutes, while Jakub Blaszczykowski added the second and Ivan Perisic wrapped up the scoring in the second half.
Borussia Monchengladbach were 2-0 winners over Alemannia Aachen, Juan Arango and Havard Nordveit with the goals, while strikes by Simon Rolfes Karim Bellarabi, Stefan Kiessling and Junior Fernandes lifted Bayer Leverkusen to a 4-0 win over Carl Zeiss Jena.
Stuttgart were also 4-0 winners, against Falkensee-Finkenkrug, thanks to goals by Vedad Ibisevic, Martin Harnik (two) and Tunay Torun.
Freiburg were made to work harder before booking their place in round two with a 2-1 win at Viktoria Hamburg.
Max Kruse opened the scoring for Freiburg only for Jakob Sachs to level a minute later, but the Bundesliga side got the job done after the break with Sebastian Freis hitting a late winner.
Elsewhere in Saturday's early kick-offs, Duisburg were 1-0 winners over Hallescher, St Pauli defeated Offenburg 3-0 and Cologne were 2-1 winners at Unterhaching.
The push for more color on their cleats, adidas has added the infrared colorway to the adiZero f50 Line.
Chelsea won the Europa League on Wednesday. The Blues defeated Benfica 2-1 on injury time goal from Ivanovic.
Bayern Munich are kings of Germany and hope to be crowned kings of Europe at Wembley later this month!
One of the top soccer cleats for control the Nike CTR360 will not let you down on the field in tight spaces.
The adidas Nitrocharge is the most talked about new cleat in years. It was released on May 15 and will take your pitch by storm.
The Juventus jersey for the 2013/14 was released earlier this week. Be the first to wear the colors of the Old Lady.
The Liverpool 2013/14 soccer jersey is available for pre-order. The Reds are eager to compete for silver next season.
Borussia Dortmund hears Wembley Calling and are headed to London for the Champions League final.
adidas has added some color to the Predator line with this new colorway. Released on May 17. Be the first to own a pair.
The new PUMA evoSPEED 1.2 FG. A great new soccer cleat with classic look and first time for PUMA to be on the cleat.