The Los Angeles Dodgers bring the National League's best record - and a three-game winning streak - to Coors Field tonight when they open a three-game series with the host Colorado Rockies.

The Dodgers, among the most controversial teams in the majors over the last few seasons with a swirling ownership controversy, got much of their front- office house in order during the offseason and have burst from the gate to take a four-game lead in the West Division.

They completed a three-game sweep of the Washington Nationals on Sunday at home, when Chris Capuano struck out nine over 6 2/3 scoreless innings en route to a 2-0 decision.

James Loney knocked in both runs for the Dodgers, while Capuano (3-0) gave up just three hits and two walks in the win. Kenley Jansen walked two in the ninth but struck out the other three batters he faced to record his second save of the year.

Los Angeles is four games ahead of San Francisco, five up on Arizona and 5 1/2 ahead of the Rockies, who enter having lost the final two games of a weekend series with the New York Mets, including Sunday's, 6-5, setback.

The Dodgers open the series with veteran right-hander Aaron Harang, who faces the Rockies for the first time with Los Angeles after 10 previous meetings in his initial 268 big-league outings.

Harang spent his first 10 seasons with three teams - Oakland, Cincinnati and San Diego - before signing a two-year deal with the Dodgers this past offseason with an option for 2014 that could pay him $15 million over the life of the contract if he meets certain innings incentives.

He won double-digit games for the Reds from 2004-07 before a prolonged skid that saw him win just 18 times in his final three years in Cincinnati. He signed a one-year deal with the Padres in 2011 and resurrected his career with a 14-7 record and 3.64 earned run average in 170 2/3 innings.

An 8-4 loser to the Padres in his initial Los Angeles outing, he's pitched at least six innings in each of his last three - allowing 18 hits and 10 runs in 18 1/3 innings that included a 4-3 win at Milwaukee and two no-decisions.

He's 4-4 lifetime with a 4.94 ERA against the Rockies.

For Colorado, Dominican-born righty Juan Nicasio aims for a fifth start of 2012 without a loss.

He's tossed 22 2/3 innings in four outings while giving up 12 runs on 26 hits and scoring one victory - an 8-4 decision over San Diego on April 18.

Nicasio has pitched 6 1/3 or more innings in three of four starts and has struck out 17 batters and walked seven.

Last season, his first in the majors, he was 4-4 in 10 starts and faced the Dodgers twice, surrendering 13 hits and nine runs in 10 2/3 innings.