How to write a codition based on min rank

Hello All,

could you please let me know how to write a codition based on min rank,

Create table TableA1 (PatID int, blockName varchar(20), RankID int)

insert into TableA1 values (123, 'Cancer', 5)
insert into TableA1 values (235, 'Hearts', 6)
insert into TableA1 values (345, 'Child' ,1)
insert into TableA1 values (123, 'OutPatient', 3)
insert into TableA1 values (567, 'OutPatient', 4)
insert into TableA1 values (789, 'Inbound' , 7)
insert into TableA1 values (567, 'OutPatient', 3)
insert into TableA1 values (678, 'Cancer', 5)
insert into TableA1 values (789, 'Hearts', 6)
insert into TableA1 values (789, 'KidneySpl', 9)
insert into TableA1 values (345, 'OutPatient', 3)

select * from TableA1 order by 1

Create table TableB1 (PatID int, ModelId int )

insert into TableB1 values (123,114346)
insert into TableB1 values (235,226554)
insert into TableB1 values (345,336544)
insert into TableB1 values (567,446789)
insert into TableB1 values (678,558987)
insert into TableB1 values (789,667998)

select * from TableB1 order by 1

--Joining
select a.*, b.ModelID from TableA1 A inner join TableB1 B
on a.PatID = b.PatID
order by 1,3

Required outcome is based on the RankID . So if for the same PatID that appears more times in TableA1, the ModelID (from TableB) goes to the record with highest rankID.

expected Results will be