Victory took the Saints back into the play-off places, with the seventh places Reds two points behind their rivals having played a game more.
The visitors were quick out of the blocks and led 2-0 before Josh Windass reduced the deficit but it was game over once Southampton went 3-1 up on the hour mark as two more goals followed.
Here’s how the players rated.
ARTHUR OKONKWO: Made two outstanding saves but could do nothing about other goals. 6
MAX CLEWORTH: Was way off it for opening half hour and won’t be happy with his part in Saints’ late goals. 5
DOMINIC HYAM: Had his hands full coping with dangerman Cyle Larin who outdid him for crucial third goal. 6
CALLUM DOYLE: The Reds defence was up against it from start to finish. 5.
ISSA KABORE: Did more in the first minutes of the second half than he did in the entire opening 45 minutes. Much better after the break. 5
GEORGE DOBSON: Smashed his already-injured wrist early on but showed bravery and urgency to get Reds back into the game. 7
LEWIS O’BRIEN: Had a really quiet game in the middle of the park where the Saints marched all over Wrexham. 5
GEORGE THOMASON: Like Kabore, got into the game more in the second half. 6
JOSH WINDASS: Showed superb composure for Wrexham’s goal as he raced onto Kieffer Moore’s knock on. 6
KIEFFER MOORE: The Welsh international was back in the starting line-up, worked hard and saw a second half header hit the foot of the post. 6
NATHAN BROADHEAD: Got Wrexham going with a header that hit the post but that was about it. 6
SUBSTUTUTES
MATTY JAMES: The veteran returned as part of a triple substitution. 5
OLLIE RATHBONE: Came on too late to make any impact. 5
RYAN LONGMAN: Replaced Kabore down the right . 5
DAVIS KEILLOR-DUNN: Given only six minutes to show what he could do. 5
SAM SMITH: Also arrived late on the night, coming on for Windass. 5