Phoenix, AZ (My Sportsbook) - The defending World Series champion Arizona Diamondbacks begin their title defense this evening, when they open their National League Division Series against the St. Louis Cardinals at Bank One Ballpark.

These two teams met a year ago in the NLDS, with the D'backs winning the fifth and deciding game by a 2-1 score in a very entertaining series. Arizona, which had home-field advantage in that matchup, secured Games 1, 2 and 5 at Bank One Ballpark in this one by virtue of finishing one game ahead of the Cardinals in the standings.

Had the two clubs ended the regular season with identical records, St. Louis would have earned home-field advantage because it won four-of-six versus the Diamondbacks this season, including a three-game sweep at Busch Stadium from September 23-25. However, Arizona swept the Colorado Rockies over the weekend and the Cardinals dropped one to the Brewers, enabling the defending champs to stay home for the first two games.

"If we don't sweep this year, we possibly don't win the division, and we're possibly getting on a plane [to St. Louis]," veteran first baseman Mark Grace told The Arizona Republic following Sunday's 11-8 win. "We don't want to go to St. Louis right now, because we got throttled there, and we'd rather have the big guy [Randy Johnson] and [Curt] Schilling pitching on desert soil. They're ready."

Randy Johnson will be on the hill tonight for the National League West champs, who finished the regular season with a 98-64 record to outlast the wild card- winning San Francisco Giants by 2 1/2 games.

Johnson (24-5, 2.32) last toed the hill on Thursday, when he held the Colorado Rockies to a pair of unearned runs on six hits over nine innings. The complete game was his third in five starts and eight overall this season. He walked two and struck out eight.

In the month of September, the flame-throwing lefthander was 5-0 in as many starts with a minuscule 0.66 earned run average. Since the All-Star break, he is 12-2 with six complete games and a 2.15 ERA. This, after going 12-3 with a 2.47 earned run average and two complete games in the first half. At home in 2002, the "Big Unit" went 14-3 with six complete games and a 2.12 ERA in 21 attempts.

The 39-year-old hurler ended the year by leading the big leagues in strikeouts (334), victories, ERA and innings pitched (260). The four-time Cy Young winner also surrendered two earned runs or less in 24 of his 35 outings.

In Game 2 of last year's NLDS, Johnson faced the Cardinals in Phoenix and was tagged with the loss after permitting three runs on six hits in eight innings of work. He battled St. Louis once during the regular season and earned a win with seven innings of eight-hit, three-run ball.

Lifetime, Johnson is 7-7 in the postseason. However, he is just 2-6 with a 4.05 earned run average in the Division Series, with both wins coming while he was a member of the Seattle Mariners in 1995.

Matt Morris counters for the Cardinals, who won the NL Central by 13 games over the Houston Astros with a 97-65 record.

Morris (17-9, 3.42) defeated the Milwaukee Brewers on Thursday in his last trip to the rubber, allowing one run six hits over seven innings at Busch Stadium. He walked one and fanned four.

The victory snapped the righthander's personal two-game slide, during which he surrendered a total of 11 runs -- 10 earned -- on 18 hits in 9 2/3 frames. The 28-year-old hurler pitched well on the road this season, compiling a 9-4 mark with a 2.91 earned run average in 14 tries. After going 10-6 in the first half of the year and earning a spot on the NL All-Star Team, Morris went 7-3 with a 3.23 ERA.

In last year's Division Series, he started a pair of games and finished 0-1 with a 1.20 earned run average. Morris, who started Games 1 and 5 in the 2001 NLDS, permitted a total of two runs on 13 hits in 15 innings of work. He faced the Diamondbacks once during the regular season and picked up the victory with seven innings of nine-hit, four-run ball.

For his career, Morris is 0-1 in six postseason outings (two starts).

St. Louis, which has won the last four meetings between these two teams, went 45-36 on the road this year. The Diamondbacks, on the other hand, finished the season with a 55-26 home record. Their 55 home victories were the most in the majors.

Game 2 of this series is slated for Thursday, when Curt Schilling (23-7, 3.23) will take on Chuck Finley (7-4, 3.80).