PITTSBURGH – Juan Nicascio took the advice of his manager Clint Hurdle before making Pittsburgh Pirates' debut -- "don't overcook things."

Nicasio kept it simple but was also dazzling, allowing one run and two hits in six innings, as the Pirates beat the St. Louis Cardinals 5-1 Wednesday to sweep the three-game series to open the season.

Signed to a one-year, $3 million contract as a free agent in December after pitching primarily in relief for the Los Angeles Dodgers last season, Nicasio (1-0) struck out seven and did not walk a batter. That followed an outstanding spring training in which he pitched 15 scoreless innings and had 24 strikeouts.

"I was just taking it hitter-by-hitter, pitch-by-pitch, just like I did in spring training," Nicasio said. "I didn't try to think too much. I just concentrated on throwing strikes and getting people out and it worked."

Hurdle was pleased.

"He was very aggressive, especially with the fastball," Hurdle said. "It was a continuation of what we saw from Juan in spring training. He did a job of carrying over the adjustments he made down in Florida."

Added Cardinals manager Mike Matheny: "It looked like he had a good fastball and a good slider. He used them effectively and was working ahead in counts, not a lot of free bases. He kept us off-balance."

It marks the first time the Pirates have opened a season 3-0 since 2007. The Cardinals (100-62) and Pirates (98-64) had the two best regular-season records in the major leagues last season while finishing 1-2 in the National League Central.

The Pirates have finished second to the Cardinals in the division race each of the last three seasons, settling for a berth in the NL wild card each year. However, Hurdle downplayed any idea that there may be a changing of the guard in the NL Central.

"We're past the point of being surprised when we play well," Hurdle said. "It's a good way to start but it's just three games."

Mike Leake (0-1) did not have such a great Cardinals' debut as he was tagged for four runs and seven hits in 4 1/3 innings. He also had three walks and only one strikeout after signing a five-year, $80 million contract in December as a free agent.

"I couldn't hit my spots," Leake said. "I couldn't throw strikes. I was just erratic. I have things to work on."

Mark Melancon retired the only batter he faced for his first save, getting Kolten Wong to hit into a force out with runners on first and second.

Andrew McCutchen and Starling Marte had two hits each for the Pirates.

The Cardinals' lone run came when rookie outfielder Jeremy Hazelbaker hit his first career home run to lead off the sixth inning in his first major league start. He played center field as Randal Grichuk got the night off after going 1-for-9 in the first two games.

Leake struggled in his first inning with the Cardinals, giving up two hits, walking two and throwing 42 pitches. Yet the Pirates managed only one run on Gregory Polanco's bases-loaded walk before Leake snared a liner back through the box by Josh Harrison to the end the inning.

The Pirates scored three runs in fifth to increase their lead to 4-0.

Francisco Cervelli's two-run double capped the inning and knocked Leake from the game. John Jaso led off the inning with a triple high off the right-field wall and continued home on second baseman Kolten Wong's off-target relay throw.

Sean Rodriguez's pinch-hit RBI double in the sixth gave the Pirates a 5-1 cushion.

NOTES: Cardinals C Yadier Molina tied the franchise record with his 1,439th game caught, equaling the mark set by Ted Simmons from 1968 to 1980. ... Cardinals RHP Matt Bowman, who was selected from the New York Mets in the Rule 5 Draft at the Winter Meetings, pitched two scoreless innings in his major league debut. ... Pirates LHP Corey Luebke, who underwent Tommy John reconstructive elbow surgeries in both 2013 and 2014, made his first appearance in a major league game since April 29, 2012 with San Diego and retired two of the four batters he faced. ... Pirates 3B Jung Ho Kang (recovering from reconstructive left knee surgery) played five innings in a minor league intrasquad game in Bradenton, Fla., and had four at-bats, though he was limited to running only to first base. ... Pirates RHP Jared Hughes (strained left lat) threw off the slope of the mound at Bradenton and is expected to throw off the top of the mound in the next few days. ... Both teams are off Thursday before opening three-game series on Friday night. The Cardinals play the Braves at Atlanta with LHP Jaime Garcia (10-6, 2.43 ERA in 2015) facing RHP Matt Wisler (8-8, 4.71 ERA in 2015). The Pirates face the Reds at Cincinnati with LHP Francisco Liriano (1-0, 0.00 ERA) opposing RHP Alfredo Simon (13-12, 5.05 ERA in 2015).