The South African started the day one shot back from the overnight co-leaders Villegas and Kuchar, with both players getting their Sundays off to hot starts with a flurry of birdies.
Van Rooyen bogeyed the first hole to drop further back. However, it was the back nine where he really came alive, carding six birdies and an eagle to come back in a staggeringly low 28.
Coming in clutch, he finished his last four holes in 4-under, finishing with a stunning eagle on the 18th hole to claim victory.
Starting the week with his 2024 PGA Tour card in jeopardy, Van Rooyen saw himself jump up 62 spots in the Tour's rankings and with the win, he has secured his playing rights for a further two years.
Eric van Rooyen WITB 2023:
Driver: Callaway Paradym Triple Diamond (9 degrees; Mitsubishi Diamana 60 TX)
Hybrid: Callaway Apex UW (17 degrees; Mitsubishi Kai'li 90)
Utility: Callaway X Forged UT (2-iron) - Tour AD DI95 X
Irons: Callaway Apex TCB (4 iron), Callaway Apex MB (5-PW) KBS Tour V 120 X
Wedges: Callaway JAWS Raw (50°, 54° & 58°)
Putter: Odyssey Toulon San Diego Putter
Ball: Callaway Chrome Soft X