Cain would take a no-hitter into the eighth, where Melvin Mora connected on a two-run homer to cut the Giants' 4-0 lead in half.
After struggling at the plate for much of the season, Sanchez had been red hot and a huge factor in the Giants' race to make the playoffs.
He's batting .325 in the month of September with nine multi-hit games, including Sunday's two-for-four showing that brought his season average up to .296.
Sanchez, who has not batted .300 or better in a season since hitting .304 for the Pittsburgh Pirates in 2007, has 45 runs batted in and 54 runs scored on the season.
San Francisco entered the day tied for first in the division with the San Diego Padres, who would lose to the Cincinnati Reds, 12-2, at home later Sunday.
The Giants (88-68) now lead San Diego by one full game in the standings.
Sanchez has never appeared in the postseason in his 10 years of major league service.
Doug Slaten (Glendale Community College, 1999) relief pitcher, Washington Nationals: Slaten hasn't appeared in a game since Wednesday, when he was charged with one earned run after walking the only batter he faced in Washington's 4-3 win over the visiting Houston Astros.
The former Vaquero had an opportunity to record a hold when he relieved starter Jason Marquis with one out and a runner at second base in the seventh inning, but he walked Anderson Hernandez, who would score the go-ahead run for Houston later in the frame.
Slaten is going through an up-and-down September, having given up runs in three of his five appearances and his season earned-run average has bumped up from 2.86 to 3.35 as a result.
He has gone 4-1 and struck out 33 batters this season for the Nationals, who are 67-89 for last place in the National League East.
Trevor Bell (Crescenta Valley High, 2005) pitcher, Los Angeles Angels of Anaheim: Bell is still listed as active on the Angels' official roster, but in reality he's been anything but lately.
Since pitching 5 1/3 innings and taking the loss in 6-1 setback against the Cleveland Indians on Sept. 7, Bell has not made an appearance, either as a starter or out of the bullpen.
He has gone 2-5 this season as a starter and a reliever, recording a 4.72 ERA with 45 strikeouts.
The Angels are 75-80 for third place in the American League West.