St. Louis @ Pittsburgh preview

Last Meeting ( May 10, 2015 ) St. Louis 3, Pittsburgh 4

The Pittsburgh Pirates look to extend their winning streak and close the gap in the National League Central when they host the division-leading St. Louis Cardinals on Thursday in the opener of their four-game series. Pittsburgh posted its fifth consecutive victory and eighth in nine contests on Wednesday, completing a three-game sweep with a 5-2 triumph over San Diego.

Gregory Polanco snapped a 2-2 tie with a two-out RBI single in the eighth while Andrew McCutchen and Jung Ho Kang each added a run-scoring base hit later in the inning as the Pirates overcame an early 2-0 deficit to secure their league-leading 10th sweep of the year. St. Louis maintained its 4 1/2-game lead over second-place Pittsburgh by rallying for a 6-5 road victory over the Chicago Cubs on Wednesday. After the Cardinals squandered a 4-0 lead, Jhonny Peralta belted a two-run homer with two outs in the ninth inning to help the team earn a split of the four-game series. The division rivals have not met since May, when St. Louis began the month with a three-game sweep at home before losing two of three in Pittsburgh a week later.

TV: 7:05 p.m. ET, MLB Network, FSN Midwest (St. Louis), ROOT (Pittsburgh)

PITCHING MATCHUP: Cardinals RH Carlos Martinez (9-3, 2.70 ERA) vs. Pirates LH Jeff Locke (5-4, 4.15)

Martinez was forced to settle for a no-decision against San Diego on Saturday after allowing just one run in 6 2/3 innings. The 23-year-old Dominican has given up two runs or fewer in nine of his last 10 starts and three in the other, going 6-2 in that span. The impressive stretch began after Martinez was tagged for seven runs on seven hits and four walks over 5 1/3 frames at Pittsburgh on May 9 in falling to 0-2 with a 6.23 ERA in 11 career games (two starts) versus the Pirates.

Locke continued his strong surge on Saturday, when he picked up the victory after limiting Cleveland to two hits in eight scoreless innings. The 27-year-old has yielded fewer than three earned runs in each of his last five outings but is only 2-1 in that stretch. Locke is 2-2 with a 3.82 ERA in six career starts against St. Louis, including a no-decision on May 10 in which he allowed three runs and five hits in 6 2/3 frames.

WALK-OFFS

1. The Pirates have allowed three runs or fewer in each game during their winning streak.

2. Summoned from Triple-A Memphis earlier in the day, 1B Dan Johnson made his debut for St. Louis on Wednesday and went 2-for-4 with a pair of RBI singles.

3. McCutchen enters the series with a 15-game hitting streak thanks to his RBI single on Wednesday.

PREDICTION: Cardinals 4, Pirates 3