The on-form forward struck with a rebound in the first half and his intervention proved enough to see Valencia maintain its flawless start to the Primera Division season
The in-form striker, who scored a hat-trick in his side's thrilling 4-3 win at home to Racing Santander on the opening weekend, and netted the only goal of the game as Valencia defeated Atletico Madrid in its next match, was on target again as he bundled home a rebound after half an hour.
Pablo Hernandez advanced down the left, riding several challenges before setting up Jonas. The Brazilian's shot was saved and the rebound fell to Soldado, in the right place at the right time as usual to convert what was the first real chance of the game.
Soldado latched onto a neat ball from Ever Banega midway through the second half, but saw his shot saved by Juan Pablo Colinas.
The striker then departed with a twisted ankle and was replaced by Aritz Aduriz, who missed a great chance to make it 2-0 soon after coming on.
Sporting piled on the pressure in the closing stages as it sought a late leveller.
Valencia keeper Vicente Guaita made a great save to deny David Barral and the home side was virtually camped in the visitors' area in the final few minutes.
However, the visitors held on to move provisionally top of the table, where they could be joined by Real Madrid and Betis on Sunday.