Two teams needing a big week in order to have a shot at the National League playoffs go head-to-head Monday night when the Colorado Rockies and host San Francisco Giants open a four-game series.

Each NL West team has eight games remaining in the final seven days of the regular season, with the winner of this series staying alive in the scramble for the NL's two wild-card playoff spots, while the loser could be eliminated from contention.

The Giants (26-26) begin the week in the better shape of the two. They will take the field Monday tied with Cincinnati (27-27) and Milwaukee (26-26) for the second wild card, all trailing Philadelphia (27-26) by a half-game.

The New York Mets (24-29) and Rockies (23-29) also remain alive, but need wins in bushels while getting help in order to potentially make it to next week.

Both the Giants and Rockies scored crucial wins Sunday against troublesome opponents.

The Giants won for the first time in six meetings with rival Oakland this season, using a Brandon Crawford grand slam as a springboard to a 14-2 win that snapped a two-game losing streak.

San Francisco had suffered 6-0 losses in each of the first two games of the series, then had manager Gabe Kapler make the surprising move of pushing back ace Johnny Cueto (2-1, 4.78) a day to face the Rockies.

The first half of the equation produced a win, with Tyler Anderson, on two days' rest, shutting out the A's into the sixth inning of the lopsided win.

Cueto, who has been battling a sore hip, faced the Rockies once earlier this season in Colorado, allowing two earned runs in five innings in a 7-6 loss.

Colorado has won four of the first six meetings; Cueto is 9-3 in his career against the Rockies, with a 2.71 ERA in 17 starts.

Kapler noted after Sunday's win that he's happy with the way his team played loosely in a crucial game, and hopes it continues this week.

"We're going to stay even," he said. "We sense the urgency; we know how important it is. But we're going to stay relaxed through this."

Meanwhile, the Rockies salvaged one win in their four-game home series against the first-place Los Angeles Dodgers on Sunday, riding Josh Fuentes' three hits and three RBIs to a 6-3 victory.

Like the Giants, Colorado held out a key player Sunday when Nolan Arenado was given a day off to rest his sore left shoulder.

Arenado has been a one-man wrecking crew in his career at Oracle Park in San Francisco, where he has 11 home runs.

The Rockies flew to San Francisco on Sunday night uncertain of their star's status.

"He was undergoing some tests," Rockies manager Bud Black explained. "We're waiting for all the results to come back on that and then we'll make a decision."

Right-hander German Marquez (2-6, 4.33) is Colorado's scheduled starter in the series opener. He beat the Giants 5-2 at home last month to improve his career record against them to 3-4 with a 6.00 ERA in nine career starts.