How can I extend my tourist visa in Thailand after arriving from abroad?

Just a quick report, might be useful for someone

In Phuket. Have TR (60+30), Russian passport, have left Thailand for a month, had a single re-entry. My 60 days expire today, 22nd of July. I have arrived to Bangkok today, 22nd of July, at 9.10 am. Had a flight to Phuket at 10.35 am. Immigration officer told me it’s tight, I said that I’m going to immigration in Phuket for an extension and asked if he could give me W30, he said yes, but stamped only for today:)

I arrived in Phuket at 12, went to immigration in town with my documents, applied for an extension and got it by 1.45pm