Swansea manager Brendan Rodgers paid tribute to Darren Pratley after the Bolton midfielder came back to haunt his former club.
Pratley brought the Trotters level in the FA Cup fourth-round tie against the Swans at the Reebok Stadium, before Chris Eagles fired a second-half winner.
However, Rodgers felt there may have been a hint of offside about Pratley's leveller.
"It was a decent header, although I felt he was probably just a fraction offside when the ball came in," he said. "But we should never have got to that point.
"I am pleased for Darren because he is a good lad. He has decided to leave Swansea and move here and maybe it hasn't quite worked out how he wanted.
"(But) there is no doubt that he will show he is a really good player for Bolton."