Son, named Korean captain with regular skipper Ki Sung-yueng left on the bench, gave his side the lead just before the hour mark and debutant Moon Seon-min added the second 18 minutes from time.
Shin handed highly rated Hellas Verona midfielder Lee Seung-woo his senior debut in midfield and the former Barcelona B youngster put on a lively display to push his case for inclusion in the final 23-man squad.
Lee and Son carried much of the attacking threat and the Tottenham Hotspur forward put his side in front in the 60th minute when Lee found him with the time and space to smash a shot past goalkeeper Donis Escober from well outside the area.
Moon doubled the advantage twelve minutes later when he skipped past a challenge to score after impressive work down the flank by Hwang Hee-chan.
South Korea kick off their World Cup campaign on June 18 when they meet Sweden before facing Germany and Mexico in Group F.
(Reporting by Michael Church, Editing by Christian Radnedge)
