The man was cursing around kids and appeared to be instigating a fight, according to SFPD, so the policemen identified themselves. But the man retreated, police said, not complying with the officers' demands.
"Once cornered, the suspect took a fighting stance with one of the officers and was quickly subdued and placed under arrest," police said.
This undercover strategy already got some media attention in June, when the department announced that officers would be sporting Dodgers gear during the NL West rivals' three-game series at AT&T Park.
And after the violence that erupted during last year's Raiders-Niners pre-season match-up at Candlestick, it's not really that surprising the cops maintained a stealth presence at the stadium.
Apparently, the strategy is not reserved for only the highest-tension contests -- yet here it was, at a pre-season game against a non-rival team with famously a benign fan base.
Still, the heckler was charged with disturbing the peace, resisting arrest, and public drunkenness. He was booked in county jail. The night wasn't all bad for him, though -- the 49ers won 35-3.