(Reuters) - The St Louis Cardinals moved within one win of returning to the World Series with an 8-3 romp over the San Francisco Giants in the National League Championship Series on Thursday.

Starter Adam Wainwright stymied the Giants with a sharp-breaking curve ball, while the Cardinals scored two runs in the first and added two more in the fifth, sixth and seventh innings to take a commanding 3-1 lead in the best-of-seven series.

Matt Carpenter, whose two-run home run as a mid-game substitute propelled the World Series champion Cardinals to victory on Wednesday, reached base three times and scored twice, while Matt Holliday, Yadier Molina and Jon Jay drove in two runs apiece.

Wainwright went seven innings, allowing four hits and one run, on a solo homer by Hunter Pence. Pablo Sandoval hit a two-run homer off reliever Fernando Salas to complete the scoring. Tim Lincecum was the starter and loser for the Giants.

St Louis can clinch a World Series place against American League champion Detroit Tigers with a home win against San Francisco on Friday when Cards starter Lance Lynn is scheduled to take the mound against Giants left-hander Barry Zito.

(Reporting by Larry Fine in New York, Editing by Greg Stutchbury)