The Germany coach was visibly pleased with his side's 4-2 win over the Ethniki, but remained cautious over a possible meeting with England or Italy in the last four
The 52 year old trainer, who oversaw Germany's record-breaking 15th consecutive win, waxed lyrical over his side, before remaining cautious over the identity of its semifinal opponents.
"It is an achievement of class by this team [to have reached a semifinal for the fourth consecutive time]. I think, we all can be proud of this team." Low told German broadcaster ZDF.
Captain Philipp Lahm opened the scoring with a fine swerving strike before Fernando Santos' men scored a shock equalizer through Georgios Samaras early into the second half.
Sami Khedira fired home a sumptous volley to retake the lead, before Miroslav Klose and Marco Reus made it 4-1. Dimitris Salpingidis converted a penalty late on, which proved mere consolation as die Mannschaft progressed to the last four for the fourth tournament running.
"This team [Greece] again had one chance and scored two goals. We missed out on scoring in the beginning. But we kept going and scored lately. It was important that we showed a reaction after [being pulled back to]1-1," Low said.
"It was a day of changes. After three wins in a row, I had the feeling I had to change something and bring some fresh air into the team. It was the time to change something."
Germany plays the winner of the fourth quarterfinal between England or Italy in Thursday's semifinal. Kickoff at the National Stadium in Warsaw is at 2:45 p.m. ET.