For the third time in four starts, Pittsburgh farmhand Justin Wilson was dominant. But like the other two games when he allowed just one hit, the left-hander was not rewarded with a win.

Pittsburgh's No. 9 prospect allowed a lone single and issued one free pass while striking out four batters over six shutout innings Monday, as the Triple-A Indianapolis Indians beat the Louisville Bats, 6-4, in 14 innings.

Selected in the fifth round of the 2008 Draft, Wilson set down the side in order in the first inning and he worked around hitting Felix Perez with two outs in the second.

Kristopher Negron stroked a one-out base hit to left field in the third frame and Paul Janish followed that with a walk. But no other Louisville batter reached base against Wilson, who retired the final 10 batters he faced.

The Fresno State product turned a 3-0 lead over to the bullpen in the seventh, but the Bats rallied to score three times to ensure he would not factor in the final decision.

The outing lowered Wilson's ERA to 3.34, and it marked the third time in four starts that he has allowed one hit while pitching six innings.

On June 17, he gave up a run on one hit and three walks in a 2-1 win over Charlotte. Five days later, he replicated that line in a 4-2 victory at home against the Scranton/Wilkes- Barre Yankees. Wilson did not factor into the decision in either game after exiting both contests in a 1-1 tie.

Wilson has allowed two hits or fewer in six of his 17 International League starts this season. Among those performances was a 7 1/3-inning no-hit outing he spun on the road in Durham on April 29 in his fifth start of the year.

Now in his fourth year of pro ball, Wilson went 6-8 with a 4.50 ERA in 26 starts with Lynchburg in 2009 and he posted an 11-8 record and a 3.09 EA in 27 appearances with Double-A Altoona in his sophomore year.

Last season -- Wilson's first year in the International League -- he won 10 games (10-8) and recorded three saves with the Indians. He finished with a 4.13 ERA over 30 appearances, including 21 starts, in Triple-A.

On Monday, Kris Johnson (4-0) allowed one hit while striking out one batter over two innings to earn the victory, and closer Tim Wood fanned two batters in the 14th inning to earn his 12th save.

MLB.com's No. 32 prospect Starling Marte was 3-for-6 with a double, a walk and an RBI, and first baseman Matt Hague was 2-for-5 with a double, two walks and four RBIs. Hague snapped a 4-4 tie with a bases-loaded, two-run single to left field in the top of the 14th inning.

Louisville reliever Nick Christiani (0-4) surrendered two runs -- one earned -- on two hits and a walk while striking out three batters. Right fielder Bill Rhinehart smacked a two-run homer in the loss.