The league leaders scored first through Patrice Evra in the 16th minute at the Liberty Stadium before Swans star Michu tallied his 13th league goal just before the half-hour mark in the 1-1 draw.
Despite the result, Ferguson felt his United side deserved to win with the way they went about heaping pressure on the home team with their 20 attempts at goal and 60% possession.
"We absolutely battered them. It was a great performance in the second half. It is unbelievable we didn't win the match," Ferguson said.
"My only criticism is that the final ball at times let us down. "No criticism of the performance, it was very good."