Pirates 7, Cardinals 1: Russell Martin highlighted a five-run third inning with a three-run homer as host Pittsburgh cruised to victory in the battle for first place in the National League Central.

A.J. Burnett worked seven strong innings and Neil Walker went 3-for-4 with an RBI for the Pirates, who took a one-game lead over the Cardinals in the division. Pittsburgh, which has outscored the Cardinals 12-1 over the first two games of the series, improved to 10-5 against St. Louis this season.

The Pirates took a 2-0 lead on back-to-back RBI singles by Burnett and Jose Tabata in the second inning. Carlos Beltran halved the deficit with a run-scoring base hit in the top of the third before Pittsburgh broke open the contest in the bottom half against Lance Lynn (13-9).

Marlon Byrd began the uprising with an RBI single and Garrett Jones walked before Martin deposited a 2-1 offering from Lynn over the center-field wall for a 6-1 advantage. Walker capped the rally with a run-scoring triple as the Pirates handed the Cardinals their third straight loss.

Burnett (7-9) limited St. Louis to one run and four hits, walking one and striking out six. Lynn was tagged for seven runs and 10 hits over four innings as he suffered his fourth consecutive loss.

GAME NOTEBOOK: Less than a week after adding Byrd and C John Buck in a deal with the New York Mets, Pittsburgh acquired 1B Justin Morneau from the Minnesota Twins on Saturday for OF Alex Presley and either cash or a player to be named. ... 1B Allen Craig recorded two of the six hits for St. Louis, which has scored a total of one run during its skid. ... RHP John Axford made his debut with the Cardinals after being acquired from Milwaukee on Friday. He tossed a perfect seventh inning.