Edgar Santana pitched a scoreless ninth to complete the shutout.

Adam Frazier was 2-for-4 with a double, a triple and two runs scored for the Pirates, and Corey Dickerson was 2-for-4 with an RBI double and a run scored.

The Pirates, who had lost 10 of 13, put themselves in position to win a series after losing four straight.

Taillon (3-4) allowed four base runners, on three singles and a walk, and struck out six while racking up 104 pitches. Two of those hits came in the fifth, putting Marcell Ozuna and Dexter Fowler on first and second with no outs, but Taillon struck out Yairo Munoz and Kolten Wong and got Francisco Pena to ground out.

Taillon had four losses and five no-decisions since he pitched a complete-game, one-hit shutout April 8 against Cincinnati.

St. Louis starter Miles Mikolas (6-1) allowed two runs, one of them earned, and six hits in six innings, with two strikeouts and one walk.

Pittsburgh opened the scoring in the third.

Frazier -- a last-minute addition to the lineup because Josh Harrison developed flu symptoms -- hit a one-out double off Mikolas' foot. Mikolas then hit Francisco Cervelli, the ninth time the Pirates catcher has been struck by a pitch. Starling Marte reached on Munoz's error at short to load the bases. Frazier scored on Josh Bell's sacrifice fly to make it 1-0.

In the fifth, Frazier hit a one-out triple to right and scored when Cervelli followed with triple to left for a 2-0 Pirates lead.

Against St. Louis reliever Sam Tuivailala in the eighth, Bell drew a one-out walk and scored on Dickerson's double to make it 3-0, with Dickerson moving to third on the throw home. Mike Mayers replaced Tuivailala and gave up a sacrifice fly to Colin Moran for a 4-0 Pirates lead.

--Field Level Media