After successfully shutting down one team that had bothered him all season last weekend, the ace left-hander will look to avenge another as he leads the Los Angeles Dodgers against the Colorado Rockies in Friday night's series opener.Kershaw (15-9, 1.88 ERA) is on pace to finish the year with baseball's lowest ERA since Houston's Roger Clemens closed 2005 at 1.87. The favorite for the NL Cy Young Award, Kershaw leads the league with 224 strikeouts, and will likely become the first Dodger pitcher with a sub-two ERA since Sandy Koufax's 1.73 in 1966.Kershaw has allowed two earned runs or fewer in 11 of 12 starts since the All-Star break. The lone exception came Sept. 2, when he yielded season highs of five runs and 11 hits in five innings against the Rockies (72-87).Kershaw has returned to his usual self since, posting a 1.71 ERA in three starts. Pitching on seven days' rest Saturday, he tossed seven innings of three-hit ball in a 4-0 win over a San Diego team responsible for three of his losses this season."I felt good, so I guess that's a bonus," said Kershaw, whose next start will come in Game 1 of the NL division series on Thursday. "A little bit erratic at first with the fastball but (catcher A.J. Ellis) did a real good job of making me use all my pitches on both sides of the plate."The Rockies have done more than challenge Kershaw this month. They lead the majors with a .303 batting average in September, and have tallied at least nine hits in nine straight contests.The retiring Todd Helton is batting .387 over a seven-game hitting streak with two home runs, six doubles and nine RBIs.Despite their potent offense, a 5.84 team ERA in September has left the Rockies with an 8-14 record.Scheduled starter Collin McHugh (0-3, 8.59) is among the struggling Colorado pitchers.Acquired from the New York Mets in June, McHugh has yet to make much of a mark in Denver. The right-hander, shuttled back and forth between the minor leagues and the majors all season, has surrendered a .379 average, including a .421 clip to left-handed batters.After allowing one run in five innings to St. Louis in his return to the major leagues on Sept. 16, he regressed Saturday, allowing six runs and a season-worst 11 hits in five innings of a 7-2 loss to Arizona."It was kind of disappointing, too many balls up in the middle of the plate," McHugh said. "I had success the last outing keeping the ball down and out of the middle of the plate. Today we got beat on a couple of big spots in the middle of the plate up."The NL West champion Dodgers (91-68) have scored 13 runs over their last six games.Despite three doubles and a triple, they left seven men on base in Thursday's 3-2 loss at San Francisco. They are 6 for 44 (.136) with runners in scoring position in their last six.Yasiel Puig is 7 for his last 37 (.189) overall, but is batting .346 (9 for 26) against Colorado.The Rockies are one of four major league teams with a winning record at Dodger Stadium this year, having won four of seven.