Australia wasted a number of chances in the second half before scoring their third in added time when Foord converted a penalty to hand 36th-ranked Argentina their third defeat in as many matches in the four-team tournament.
Australia, coached by Ante Milicic and ranked sixth in the world, are grouped with Italy, Brazil and Jamaica in this year's World Cup in France.
They play a friendly with defending world champions United States next month in their final warm-up for the June 7-July 7 tournament.
Earlier, Ji So-yun and Moon Mi-ra scored for 14th-ranked South Korea, who beat New Zealand 2-0 to finish as runners-up with six points from three games.
Chelsea midfielder Ji unleashed a powerful shot from outside the penalty area in the 74th minute to claim her fourth goal of the tournament before fellow substitute Moon doubled the lead.
New Zealand finished third in the standings with three points ahead of Argentina.
(Reporting by Shrivathsa Sridhar in Bengaluru; Editing by Sudipto Ganguly)
