How do I use Click Element function with robot framework when the element does not have id or name?

I'm currently using the Selenium2Library in robot framework to automate some web tests. Currently, I'm having problems automating the click of a login button with the Click Element function.

This is the element I would like to use:

<a class="transparentBtn loginLink ng-scope" ng-click="commonService.gigyaRaasLogin()" translate="BTN_ADMIN_LOGIN_WATCHLIST">LOGIN</a>

and this is the xpath if I copy from the console: //*[@id="menu"]/div/div[5]/div/div/div[2]/ul/li[2]/a

I have trouble finding which locator to use if I want to click this element.

These are some of the things I've tried so far:

1. Click Element css=a.loginLink
2. Click Element link=LOGIN