The victory ensures Kenny Jackett's side have won nine in a row for the first time in their history and remain at the top of the table.
Striker Sako headed in James Henry's cross from point-blank range to open the scoring after nine minutes before the latter hit a post minutes later with a rasping drive.
Noaha Dicko scored his 10th goal in as many games for Wolves after 19 minutes when he fired home left-footed and Sako made the points safe 15 minutes later when he beat the offside trap to finish past Tyrell Belford.
Michael Smith dispatched Alex Pritchard's cross to pull one back for Swindon in the 76th minute, but Leon Clarke clipped in a fourth goal in injury time to notch his 16th of the season.
The result leaves play-off chasing Swindon with only one win in nine league games and facing a tough task to break into the top six.