The Orange Box

Host a game on system link, choose red team and just wait until time ends.

You simply need to host a System Link game, set the map to "Dustbowl" the time to "15 Minutes", Round Win Limit to "1". Remember to select the defending team and start it up.

The achievement will unlock as soon as the time expires.

Note: You do not need a second player/console.

This is a hard achievement if you are on an uncoordinated team. You’ll need an engineer or two and some demoman/soldier classes. Don’t put all of your defense on the point. Have one engineer set up in a good spot outside to prevent an uber-charge from wiping both sentries out. The first point is very easy to capture so coordination is the key to success here. Try to keep them back towards their spawn but don’t stray too far from the point.