Turn off Awesomium in game (there's some tools for that, ask around);
Turn postprocessing off;
Lower your resolution;
Use vertex lighting without dynamic lights;
Get rid of all the bloatware you have installed.
while your ingame you can open task manager and end the awesomium process that is the only way to do it from what i can tell.
Then when you finished that game you have to reload the full ql client all over again. it shouldnt be kicking in at all while ingame, why it does is a mystery to me... wish they could use something else because its a big fail imo and the reason we get this retarded pretend lag shit.