Question
A nicely cared for lawn with special grasses (unknown by gardener-homeowner has knowledge)
has recently been growing a clover which is rapidly overtaking the whole lawn, jeopardizing the landscaping.
How to rid the lawn of the clover while saving the lawn from any damage, from clover and clover eradication techniques.
This is a partial shade lawn, near some old growth fir trees at the top of a ravine in SW Portland Oregon.  The lawn is about 40 years in maturity, and the clover is a recent growth and it has suddenly flourished this summer.
SW Patton Ct, Portland, Oregon 97201

Answer
In early fall, as daytime temperatures comes below 80F consistently, spray the clover with Round-Up (or another broadleaf herbicide). Do not use in hot summer months.

Fertilize your lawn in late spring, early fall and late fall after that. A well fertilized lawn usually is able to keep clover at bay.