English import Vikai Kelley and captain Tyler Jones played decisive roles as the home side chased down the target of 203.
Kelley continues to prove one of the recruits of the season.
After taking 3-46 with the ball, his all-round talents came to the fore with the willow.
He blasted seven fours and three towering sixes in a sublime 87, his best knock since joining Leitchville-Gunbower.
Kelley now has 218 runs at 31.14 and 11 wickets at 13.54 this campaign.
Jones, one of the league’s premier batsmen, displayed impressive touch from the get-go.
His sparkling 76 from 95 deliveries was full of power, headlined by five massive sixes and five fours in 104 minutes of exquisite batting.
Jones (387 runs at 64.5) now has three half-centuries and a ton for the season.
Leitchville-Gunbower overhauled the target with four wickets down and took the rest of the afternoon for the middle and lower order to get valuable batting practice.
Blake Gelletly was one who enjoyed some sustained time at the crease, scoring an unbeaten 24, his best knock of the season.
Despite defeat for the Swans, Echuca South did provide the man of the match.
Asantha Singappuli followed up his 99 on day one with a marathon bowling spell on day two.
The Sri Lankan ace bowled 35.1 overs in the heat, returning the figures of 6-105.
His victims included Kelley, Josh O’Shea, who fought hard to score 26, and Liam Keath.
Shanaka Silva proved a good foil with 2-48 from nine overs.
The loss leaves Echuca South anchored to the bottom of the John McMahon Shield ladder with one win for the campaign.
The game
Leitchville-Gunbower 275 (V. Kelley 87, T. Jones 76, J. O'Shea 26, A. Singappuli 6-105, S. Silva 2-48) d Echuca South 202 (A. Singappuli 99, J. Rosin 31, V. Kelley 3-46, L. Keath 2-10, J. Keath 2-20, J. Wilson-Keir 2-23)
7°C