The match had a dramatic ending with Souths forward Jai Arrow hitting Titans half Jayden Campbell high in the final minute in front of the posts with no penalty awarded.
Captaining the side from left centre Mitchell had a raft of sublime touches that turned the match in his first game in six weeks due to a quadriceps injury.
The battle for the wooden spoon is set to go down to the wire.
The Rabbitohs, without 10 stars, moved to 18 points with their seventh win of the season, two points clear of the Titans.
Souths coach Wayne Bennett has not claimed the spoon in 37 years in the premiership, despite getting one in 1981 while coaching Brothers in the Brisbane Rugby League.
Titans coach Des Hasler has not had that ignominy since entering the coaching ranks. Bennett has one advantage in avoiding his first spoon as the Rabbitohs still have a bye to come
The Rabbitohs had drama on match eve when utility Brandon Smith was questioned by police on arrival at Coolangatta Airport but he was released without charge and took his place on the bench.
Smith was excellent with his scheming efforts giving Souths momentum.
Mitchell made an immediate impact with a slick catch and pass for winger Alex Johnston to score his 208th career try.
He then pulled off an incredible try saver when Campbell was about to put the ball down under the sticks before Mitchell smashed him and jolted the ball free.
The Titans would not be denied when winger Jaylan De Groot scored out wide and skipper Kieran Foran put barnstorming back-rower Beau Fermor in.
Rabbitohs winger Bayleigh Bentley-Hape sliced through to give the visitors a 14-12 lead at the break.
Mitchell genius gave Johnston his 209th try. He leapt high to snaffle a Jamie Humphreys bomb and followed that up with a freakish flick pass to put the dashing winger over.
Titans hooker Sam Verrills darted over from dummy-half in his 100th NRL match despite the protestations of Mitchell.
The Rabbitohs have won 10 straight matches against Titans, the first time they have done so against one club since 1967-1972 against Newtown.
The Titans lost prop Moeaki Fotuaika due to illness on match day. They faced further adversity when centre Brian Kelly was ruled out of the match with concussion and winger Alofiana Khan-Pereira left the field in the second half with a hamstring complaint.
