It was their first win in six matches but the Germans, who leave for Russia in four days, rarely put their foot on the gas, seemingly fearful of any last-minute injuries, while the Saudis confirmed their good form heading into the World Cup.
"I have no concerns after this game," said Germany coach Joachim Loew. "We will improve and once the tournament starts we will be ready.
"We eased off in the second half, defensively we need to work a bit better and not leave so many open spaces. Overall we squandered too many chances and allowed far too many chances."
With keeper Manuel Neuer starting for the second consecutive game after a nine-month injury break and Jerome Boateng also back from a muscle injury, Germany fielded as close as they could to their tournament team.
Mesut Ozil was left out of the squad, recovering from a minor knock on the knee, but they quickly went ahead with Timo Werner finding the net from an assist by Marco Reus.
Yet they failed to maintain the tempo and their defence suffered a few lapses of concentration as the Saudis showed off their speed and skill, putting central defender Mats Hummels under pressure in the first half.
Omar Hawsawi scored an own goal just before the break after Germany twice hit the woodwork and they could have added a few more were it not for a string of fine saves from Saudi goalkeeper Abdullah Al-Mayouf.
"Maybe we were lacking a bit of strength after the (two-week) training camp but next week we will be fresher and stronger," Loew said.
The Saudis pulled a goal back when Taisir Al-Jassim scored on the rebound after Marc-Andre ter Stegen saved a penalty in the 85th minute and he missed a golden opportunity to level in stoppage time.
Germany's Ilkay Gundogan, who came on in the second half, had to endure his every touch of the ball being whistled and jeered for a second straight game. German fans are angry over a picture he took with Turkish president Tayyip Erdogan last month, addressing him in a message as "my president".
Germany are in Group F along with Sweden, South Korea and Mexico. Saudi Arabia take on hosts Russia in the tournament's opening match on June 14 and also play Egypt and Uruguay in Group A.
(Reporting by Karolos Grohmann; Editing by Toby Davis)
