As per Lawkidunya and section 13 of CPC, a foreign judgment shall be conclusive as to any matter thereby directly adjudicated upon between the same parties or between parties under whom they or any of them claim litigating under the same title except.
(a) Where it has not been pronounced by a Court of competent Jurisdiction ;
(b) Where it has not been given on the merits of the case;
(c) Where it appears on the face of the proceedings to be founded on an incorrect view of international law or a refusal to recognise the law of Pakistan in cases in which such law is applicable;
(d) Where the proceedings in which the Judgment was obtained are opposed to natural justice ;
(e) Where it has been obtained by fraud ;
(f) Where it sustains a claim founded on a breach of any law in force in Pakistan.

Also a foreign judgment, even in terms of section 44-A CPC, (wherein direct execution can be filed on the basis of such foreign judgment), is not conclusive, and is subject to satisfaction of exceptions as contained in section 13 CPC by virtue of sub section (3) of section 44-A CPC.

What is the Principle of Foreign Judgement

In law, the enforcement of foreign judgements is the recognition and enforcement in one jurisdiction of judgements rendered in another (“foreign”) jurisdiction. Foreign judgements may be recognized based on bilateral or multilateral treaties or understandings, or unilaterally without an express international agreement.

Are Foreign Judgements Enforceable in Pakistan

In Pakistan, enforcement of foreign judgments is done on the basis of principle of reciprocity, that is if the country from which the judgment arises does not recognize the judgments of Pakistani courts, local courts shall not directly enforce such judgment of the foreign court as an executing court.