After a solid if unspectacular season so far, the 24-year-old German took victory for the first time with a consistent performance in the opening event in Austria.
Frenzel's winning margin was 20.4seconds but, despite being made to work harder to claim the double in Seefeld, he stood up the challenge to boost his overall World Cup title hopes.
He clocked a winning effort of 25:19.9minutes with Mikko Kokslien second just 2.9 behind while American Taylor Fletcher recorded the same time but had to make do with third.
Once again it was consistency that proved the winner in Seefeld with Frenzel seventh overall in the ski jump with a score of 118.7 and then 12th quickest in the cross-country for the win.
In contrast Haavard Klemetsen led after the jumping but was only 38th fastest during the cross-country as he ranked 24th with Taihei Kato, second after the jumping, ending 16th overall.
Kokslien made up over a minute to finish second with the second-best cross-country time after ranking 14th in the jumping while Fletcher was the quickest to move up from 21st to second.
Jason Lamy Chappuis, who was 15th again, still leads the overall World Cup standings but Magnus Moan, who was sixth, is just 19 points behind with Frenzel 34 shy of the Norwegian in third.