Striker Yahya Dagriri opened the scoring for Saudi Arabia in the 17th minute and Alfahmi Yasir doubled the lead in the 27th at the Centenario stadium in Armenia.
In the second half, Mohammed Alfatil scored in the 58th, Yasir Alshahrani in the 66th, Ibrahim Alibrahim in the 83rd and Salem Aldawsari in the 89th.
Guatemala, which lost its opening game 5-0 to Nigeria, was eliminated from competition.
''We were nervous after the first goal and missed too many passes,'' Guatemala's Paraguayan coach Ever Almeida said. ''It was an honor to come here. The players did everything possible, but football is more than just heart.''