When Lamb was recalled, the Pirates were involved in a three-team scramble for the National League East Division championship. Lamb worked in 23 games out of the Bucco bullpen, losing his only decision (September 17 against the Philadelphia Phillies) but collecting three saves. His earned run average was as low as 1.54 through his first 16 outings and 19 innings pitched, but he faltered toward the end of the season and finished with a 2.78 ERA. The Pirates captured the division title, but Lamb did not appear in the 1970 National League Championship Series, won by the Cincinnati Reds in three straight games.