Pontefract Collieries saw their unbeaten start to the season in Division One of the Toolstation NCE League ended when they made the short trip to play Selby Town on Tuesday night.
Victory could have moved Colls level on points with leaders Winterton Rangers with two games in hand, but they suffered a 3-1 defeat.
Mark Whitehouse scored their only goal on 29 minutes.
Colls lost their 100 per cent league record last Saturday when they were held to a 1-1 draw at home to Grimsby Borough.
In a rare goalless first half for the Ponte side this season, they did go close twice with Kane Reece and Whitehouse forcing saves from the keeper.
They looked on course for a win when Mickey Dunn cut in well to net his ninth goal of the season eight minutes into the second period.
But Grimsby, who have also made a good start to the campaign and had won their previous four league games, hit back quickly with Jack Bradbury netting just four minutes later.
Both sides were denied penalties after big shouts, Dunn going down for Colls, and the game ended with honours even.
Pontefract play a top of the table clash this Saturday when they host Winterton Rangers (3pm).