I was in a similar situation once. Untowered field that lay just outside of Class C airspace, though the pattern passed under it.
One afternoon I was departing east, climbing and preparing to turn crosswind at 1000 AGL. I had announced my departure like usual, but otherwise the channel was quiet. I was maybe 750 AGL when I noticed a tiny sparkle directly in front of me (fortuitously, the sun was at my back). After observing it for a couple of moments and realizing that it didn't appear to be moving relative to my position, I re-announced my departure and angled to the right (SOP in head-on convergence is everyone turn right, immediately). Sure enough, about 20 seconds later the inbound aircraft zipped past on my left. Hard to estimate distance in the air, but way less than a mile and equal altitude. Fucker never said a word, just landed straight in, with the wind, completely ignoring the pattern. Blows my mind to this day.
One afternoon I was departing east, climbing and preparing to turn crosswind at 1000 AGL. I had announced my departure like usual, but otherwise the channel was quiet. I was maybe 750 AGL when I noticed a tiny sparkle directly in front of me (fortuitously, the sun was at my back). After observing it for a couple of moments and realizing that it didn't appear to be moving relative to my position, I re-announced my departure and angled to the right (SOP in head-on convergence is everyone turn right, immediately). Sure enough, about 20 seconds later the inbound aircraft zipped past on my left. Hard to estimate distance in the air, but way less than a mile and equal altitude. Fucker never said a word, just landed straight in, with the wind, completely ignoring the pattern. Blows my mind to this day.