San Diego continues to rate as the lowest-scoring team in the majors but the Padres can reach the .500 mark by defeating the host San Francisco Giants on Tuesday. San Diego scored six runs while winning the series opener - matching a season-best output - and stands 3-1 against the Giants this season. Light-hitting reserve catcher Rene Rivera had the best game of his career with a homer and five RBIs in Monday's 6-4 victory.San Francisco had a four-game win streak halted in the opener and holds a half-game lead in the National League West over the Colorado Rockies. The Giants had nine hits in Monday's loss, a much better showing than when they had 12 hits total while losing two of three to the Padres earlier this month. Outfielder Michael Morse had three hits and two RBIs on Monday and second baseman Brandon Hicks homered for the second straight day.TV: 10:15 p.m. ET, FSN San Diego, CSN Bay Area (San Francisco) PITCHING MATCHUP: Padres LH Eric Stults (1-2, 4.15 ERA) vs. Giants RH Matt Cain (0-3, 4.35)Stults' only victory in five starts came against the Giants when he limited them to one run and three hits in six innings April 19. He received a no-decision in his last turn when he gave up two runs and 10 hits in 5 1/3 innings against Washington. Stults is 7-4 with a 4.97 ERA in 18 career appearances (16 starts) against the Giants.Cain lost to the Padres on April 18 despite allowing one unearned run and four hits over seven innings. It dropped his career mark against San Diego to 7-12 despite possessing a 3.04 ERA in 32 starts. Cain was torched for seven runs and 10 hits in six innings in his last outing while receiving a no-decision against Colorado.WALK-OFFS 1. San Francisco 1B Brandon Belt is 0-for-15 with 10 strikeouts over the last four games.2. The Padres' bullpen has the lowest ERA in the majors (1.94) and combined for 3 2/3 scoreless innings Monday with closer Huston Street improving to 10-for-10 in save opportunities.3. Giants 3B Pablo Sandoval is 12-for-24 against Stults and C Buster Posey is 7-for-17 with a homer.PREDICTION: Giants 4, Padres 3