Save plants? or fruits? The problem with LB is that it may take 3-4 days to see it... in other words, the plant may look normal but be infected because of the delay time.
If the watery dark patches are on the stems & vines, the plants are pretty much goners. If you just have it on some leaves, remove those leaves, put them in a plastic bag & seal it to remove whatever disease you can see. Out of about 60 plants at my house here, only 5 have LB on some leaves. Every morning, I remove leaves and stick them in a plastic bag from the newspaper and knot it closed and stick in the sun til garbage day. Then I spray a fungicide after that, about every 5 days. Hot dry weather & regular fungicide spraying keeps it in check if you remove all visible signs.
The best way to fight LB is to use fungicides as preventatives before any disease is present. Next year, I will begin spraying as early as 6" tall plants, even before they go in the ground! If you are organic, use copper fungicides, though they aren't very effective; another item is called Serenade, though the jury is still out on it against Late Blight.
If not organic, use Daconil or Ortho Garden Disease Control--both of these have 29.6% chlorothalonil as the active ingredient. I have been alternating these with Mancozeb, available from Bonide at garden centers. The Daconil I bought at Walmart, the Ortho at H-D. Commercial strength stuff similar to this would be Bravo, Echo (I think), Equus, and other names but the strength is 54% or even higher.
All of these are still contact or surface fungicides. There are very few systemic fungicides available to home gardeners. Systemics enter the plant and travel throughout the plant to protect it. Some are called "translaminar" or something like that, where it travels through the leaf from one side to the other. A friend just bought Previcur Flex, it was a systemic or translaminar, it was $259.95 for 2.5 gallon jug!
Surface fungicides on the other hand, you need to spray the entire plant, even the undersides of the leaves.
If you still have fruits that don't LOOK infected, if they are at least to the breaker stage where they start changing color from light green, maybe you can try removing them and somehow scrubbing them clean indoors and let them ripen there. I don't know how long they would last outdoors on the plants, especially if you still have spores around.
I still have a lot of questions myself, like why don't all my plants have it not just 5... and how long will it stay alive in the air & wind?
If anything, I would read the FAQs at the Cornell University link...http://www.hort.cornell.edu/departme...path/lbfaq.pdf
They update this with more Q&A every week or 2.
Hope this helps.