Cagliari have enjoyed a promising run including a 4-1 win away at Inter Milan since wily veteran Zdenek Zeman took over the Sardinians at the start of the season.
However Lazio had won five of the sides' past six league meetings and after Victor Ibarbo saw red in the 72nd minute the hosts survived a brief, second-half fightback at the Olympic Stadium to claim their sixth win of the season yesterday.
"I'm happy, because I've seen the fruit of the work we did leading up to the game," Lazio coach Stefano Pioli told Sky Sport.
"I'm not looking at the league standings. We'll first do that in January. Our objective is to qualify for Europe, but it's a case of taking small steps and taking it game by game."
Lazio's quickfire start was rewarded with a seventh-minute opener from captain Stefano Mauri, who bundled the ball past Alessio Cragno from close range as it ricocheted in the Cagliari box.
