Originally Posted by sushimaru

To clarify my point once again:

OW rules:

• First and Business Class customers connecting on the same day of travel, or before 6am the following day, can access the lounge when travelling between an international long haul (a oneworld international long haul flight is defined as an international flight marketed and operated by any oneworld carrier with a scheduled flight time longer than 5 hours) and an international short haul or domestic flight (and vice-versa).
• Lounge access will be determined on the international long haul ticketed flight (either First of Business Class) regardless of the ticketed class of travel on the international short haul or domestic flight.

However:

• Al Safwa First and Al Mourjan Business lounges in Doha (DOH) and Qatar Airways' Premium Lounges are excluded.

This created a confusion that needed to be checked directly with the airline.

For QR to QR connection (J with 5hrs+ flight to Y) on the same ticket at least, Al Mourjan is eligible based on the airline's response.