Lazio attacking midfielder Sergej Milinkovic-Savic opened the scoring for his side 32 minutes into the match, while Stefan De Vrij netted the second goal 11 minutes later, reports Efe.
With five minutes to go, Immobile scored the third goal and added a fourth just two minutes before the end of the game to drive home the win.
After this victory, Lazio have 67 points and hold fourth place in the La Liga table, on goal difference behind Roma, while Sampdoria remain in ninth with 51 points.
Elsewhere in the Italian football league, Inter Milan earned a 2-1 away win over Chievo Verona, continuing to chase a top-four spot.
Inter are now in fifth place with 66 points, while Chievo are in 16th with 31 points.
Atalanta jumped to the sixth position with 55 points after beating 10th-placed Torino 2-1.
Also on Sunday, 14th-placed Cagliari were held to a goalless draw against Bologna, currently in the 11th position with 39 points.
Crotone, who with 31 points are in 17th place, pulled off a 2-1 win against Udinese, currently in the 15th spot with 33 points.
Defending champions Juventus lead the Serie A table with 85 points, four points above second-placed Napoli just hours before they face off later Sunday.
(This story has not been edited by Social News XYZ staff and is auto-generated from a syndicated feed.)
