splitting by the last occurance of a dot

Dear R-helpers,

I want to split the following vector into 2 vectors by the last occurance
of a .

dput(rownames(sensext))

c("pat", "cash_bank_bal", "invest_abroad", "pat.1", "cash_bank_bal.1",
"invest_abroad.1", "pat.2", "cash_bank_bal.2", "invest_abroad.2",
"pat.3", "cash_bank_bal.3", "invest_abroad.3", "pat.4", "cash_bank_bal.4",
"invest_abroad.4", "Market.Capitalisation", "Market.Capitalisation.1",
"Market.Capitalisation.2", "Market.Capitalisation.3",
"Market.Capitalisation.4"
)

My attempt :
I tried strsplit(rownames(sensext),"\\.") but that splits it into 3 parts
sometimes,the logic of which I can see,since there are 2 dots sometimes.

Can someone tell me how to split this ?

Assuming we want to split off the number at the end try this which
splits on those dots which are followed by a digit:

strsplit(r, "\\.(?=\\d)", perl = TRUE)

Dear Gabor,

Thank you? very much. That works very well. I don't completely understand it
though. A few words on what the (?=\\d) is doing would be nice.