G.R. No. 70403 July 7, 1989
SANTIAGO SYJUCO, INC., petitioner, vs. HON. JOSE P. CASTRO, AS PRESIDING JUDGE OF THE REGIONAL TRIAL COURT OF THE NATIONAL CAPITAL JUDICIAL REGION, BRANCH LXXXV, QUEZON CITY, THE CITY SHERIFF OF THE CITY OF MANILA, THE CITY REGISTER OF DEEDS OF THE CITY OF MANILA, EUGENIO LIM, ARAMIS LIM, MARIO LIM, PAULINO LIM, LORENZO LIM, NILA LIM and/ or THE PARTNERSHIP OF THE HEIRS OF HUGO LIM and ATTORNEY PATERNO P. CANLAS, respondents.

FACTS

In 1964, the Lim siblings borrowed from Santiago Syjuco, Inc., secured by a mortgage on their properties. After failing to pay the matured obligation, Syjuco initiated extrajudicial foreclosure in 1968. The Lims sued to stop the sale, alleging usury. After protracted litigation spanning multiple courts over a decade, the Supreme Court ultimately upheld the validity of the mortgage and debt in G.R. No. L-45752 (1977), denying the Lims’ petition and rendering a final judgment.
Despite this finality, the Lims, through new counsel Atty. Paterno Canlas, filed a fresh action in 1977 (Civil Case No. 112762) to annul the same mortgage, raising identical issues of usury and fraud. The Quezon City RTC, under Judge Jose P. Castro, issued a temporary restraining order and later a writ of preliminary injunction against the foreclosure. Syjuco moved to dismiss based on res judicata and forum shopping, but the court denied the motion. Syjuco thus filed the present petition for certiorari and prohibition.

ISSUE

Whether the respondent judge committed grave abuse of discretion in refusing to dismiss Civil Case No. 112762 and in issuing injunctive relief, despite the final and executory judgment in a prior case involving identical parties, cause of action, and subject matter.

RULING

Yes. The Supreme Court granted the petition, annulling the challenged orders and permanently enjoining the lower court from proceeding with Civil Case No. 112762. The core legal logic is the impermissible violation of the doctrine of res judicata and the rule against splitting a cause of action. The prior final judgment in G.R. No. L-45752, which affirmed the validity of the mortgage and debt, constitutes a bar to the subsequent annulment case. The parties, subject matter, and causes of action (usury and fraud) are identical. The Lims’ tactic of filing a new suit to relitigate conclusively settled issues is a blatant form of forum shopping, an act of malpractice that undermines judicial finality and efficiency. The respondent judge’s failure to dismiss the case outright upon a valid plea of res judicata constituted grave abuse of discretion, as his orders were issued without jurisdiction or with excess thereof. The Court emphasized that litigants cannot vex their opponents with repeated suits over the same claim, and judges have a duty to dismiss such actions summarily to prevent abuse of process. The injunction issued by the lower court was likewise void for lacking a legal foundation, as a right already adjudged non-existent cannot be protected.