Eight thousand base-ball enthusiasts gathered at Sportsman's Park this afternoon to witness the fourth game of the world's championship series. Both clubs arrived this morning, the Browns going to their homes and Anson and his boys to the Lindell Hotel. Regarding the rumors of hippodroming the big captain said: "I know that the receipts of the Chicago games are deposited in the First National Bank. I was present when the agreement was made in Spalding's office and I heard all that passed. If we win the series the Chicago players get half the money, and that is what we are playing for." The day was bright and cool. A few minutes before the game was called it was announced that Foutz and Bushong and Clarkson and Kelly would be the batteries. The game was a most remarkable one, as the Chicagos played in fine form, but Clarkson failed to repeat his performance of yesterday. The crowd was simply brutal. They hooted and jeered at Mike Kelly, Anson, and Clarkson until the club consulted upon withdrawing from the field. In the second inning Kelly and Gleason almost came to blows. The latter ran in from third, and as Kelly was preparing to receive the ball Gleason struck him on the hands, injuring him so that play was delayed fifteen minutes. Kelly followed Gleason up and denounced him him roundly. It is feared that trouble will yet result before the series is finished.
-Chicago Daily Tribune, October 22, 1886
While the Trib's game account mentions both of O'Neil's walks, they did not mention if either was intentional. So I'm still looking around for a source that supports the idea that there were two intentional walks in the game.