Find out when it patched

I want to quickly identify the last time a server was patched/rebooted.  I'm using this PowerShell command but i want it to only find the last entry in the eventlog.  Not comb through the entire System log.  Any ideas?

-newest 1 didn't work

Get-Eventlog -computername <servername> -logname System | where {$_.EventID -eq "22"}  | Format-Table –Wrap TimeWritten,Message