It was the sixth title of the season for unstoppable Rayyan.
The reigning champions will take on Al Ahli in the final on May 12.
Al Rayyan lead Al Arabi 1-0 in the other best of three semifinals.
The Lions defeated Police to win their fifth title of the season.
Unbeaten Rayyan have an unassailable 46 points with just two rounds to go
Rayyan lead the table with 41 points while reigning champions Police are on 38
The Qatar League leaders eased past hosts Esperance Sportive de Tunis in the final
Qatar League leaders Rayyan will take on ES Tunis in the final
The Lions lead the table with 26 points from nine games while Police are second
The 42-year old guided Argentina to the Under-23 world title in August
Reigning champions Police defeated Al Khor in Friday's second match
In Monday's second match, Qatar Sports Club blanked Al Khor
Al Wakrah thrash Al Khor in the day’s first match in the Qatar League
Al Rayyan came back from a set down to get the better of Al Shamal
Borovnjak stars as Rayyan rally to beat Police in the one-off tie