Second place in the National League West — and possibly first place by the end of the series — will be on the line when the San Diego Padres and host San Francisco Giants open a four-game showdown Monday night.

Right-handers Stephen Kolek (3-1, 4.11 ERA) of the Padres and Logan Webb (5-5, 2.82) of the Giants are scheduled to get the ball to begin a series with San Diego holding a one-game advantage in the standings.

The division-leading Dodgers will begin the week just two games in front of the Padres.

The difference between San Diego and San Francisco in the standings is a direct result of a two-game home sweep by the Padres in April.

Webb also opened that series and was roughed up for five runs and nine hits in five innings in a 7-4 defeat. Xander Bogaerts and Jose Iglesias delivered consecutive two-out singles that produced three first-inning runs and put Webb and the Giants in an immediate hole.

The San Francisco ace is coming off a 2-3 May in which he served up 17 hits and nine runs (six earned) over just 10 innings in his last two starts.

The Giants lost the games 8-4 (to Kansas City) and 3-1 (at Detroit) as part of an ongoing 14-game stretch of scoring four or fewer runs.

San Francisco made four runs — three on a Luis Matos home run — stand up for a 4-2 win at Miami on Sunday, capping a 4-5 trip that bookended a three-game sweep at Detroit with 2-1 series wins over the Washington Nationals and Marlins.

“The way we’ve been scoring runs, it felt like a 20-run home run at the time,” Giants manager Bob Melvin said. “We’ll take it. It would be nice offensively to break out some and put a little distance in some of these games.”

Webb, 28, has faced the Padres 15 times, including 14 starts, going 4-4 with a 3.26 ERA in 85 2/3 innings.

Kolek didn’t face the Giants in the earlier series, but he did see them four times in relief last season. He went 0-0 with a 6.00 ERA in three total innings.

The 28-year-old blanked the Pittsburgh Pirates and Colorado Rockies over 14 1/3 innings in his first two big league starts in May. He has struggled since, giving up 15 runs (14 earned) in 16 1/3 innings against the Seattle Mariners, Toronto Blue Jays and Marlins.

In the wake of a six-game losing streak, the Padres have won three straight series — all 2-1 — over the Atlanta Braves, Marlins and Pirates.

Sunday’s come-from-behind, 6-4 home win over the Pirates included a scary moment when Gavin Sheets ran face-first into the left field fence while pursuing a home run by Adam Frazier.

Sheets was able to leave the field under his own power, but later he was diagnosed with a head contusion, sore hip and jammed wrist.

It could have been worse, Padres manager Mike Shildt said afterward.

“I think the fence is OK,” Shildt light-heartedly reported. “I think the groundskeeper is going to check on it.”

Shildt indicated that Sheets, who leads the team with 34 RBIs and ranks second in home runs with 11, would be considered questionable for the opener in San Francisco.

–Field Level Media