Saints fans were stunned when Adkins took off Lambert with 25 minutes left on the clock as his team were still in the lead.
Boss Adkins admitted: "We are good at scoring goals but we have to accept that we have conceded too many.
"It was far too open to leave Rickie Lambert on the pitch. I had to make a change and that meant bringing on fresh bodies. If you don't start Rickie Lambert or if you bring him off there will always be a question mark.
"Four points is better than none but we need to win our games at home. We've picked up another point and we just have to keep grinding away."