Rick Renteria's first two games as a big league manager ended with difficult losses. Still, he's staying positive.

In a game that took 5 hours, 55 minutes, pinch hitter Tony Sanchez singled in the winning run to give the Pirates a 4-3 victory over the Cubs on Wednesday night — the longest game in Pittsburgh history by time.

Sanchez's hit came off Carlos Villanueva (0-2), ending the game just short of 1 a.m. and 6 minutes longer the Pirates 8-7, 18-inning victory over Houston on May 27, 2006, that took 5:49.

Villanueva also allowed Neil Walker's game-ending home run in the Pirates' 1-0 win Monday in the season opener.

The Cubs left 19 runners on Wednesday night have gone 1 for 27 with runners in scoring position in their first two games.

"We did everything we could possibly do," Renteria said. "The guys kept coming back and that's a good sign for all of us. As long as we keep going out there and playing the way we're playing right now, good things are bound to happen."

Sanchez, the Pirates' backup catcher, sat through 15 innings before being called upon. However, he also played in the longest game in NCAA tournament history in 2009 when Boston College lost to Texas in 25 innings.

He did not mind playing past midnight, especially to wind up on the winning side.

"The few fans who stayed were really loud and that got the adrenaline flowing," Sanchez said. "It was a great to be in a situation where I had the chance to win a game for the first time in my career. I was getting a little nervous when I stepped up to the plate then I realized all I had to do was put the ball in play and find a hole."

Jordy Mercer opened the 16th with a bunt single but was forced out at second on Jose Tabata's sacrifice attempt. Starling Marte followed with a singled to put runners on corners before Sanchez grounded his single into left field for the walkoff hit.

Both teams scored in the 12th inning as the Cubs' Anthony Rizzo hit a leadoff home run and the Pirates' Marte had an RBI single with two outs off closer Jose Veras.

The Cubs ended a streak of 16 scoreless innings to start the season by scoring single runs in eighth and ninth inning to force extra innings.

Chicago's Emilio Bonifacio went 5 for 7 and is hitting .750 (9 for 12). Luis Valbuena added three hits, including a two-out RBI single in the ninth inning off closer Jason Grilli that tied the game at 2-2 and forced extra innings.

"I'm feeling pretty good at the plate," said Bonifacio, who signed a minor league contract with the Cubs in February after being released by the Kansas City Royals. "I'm swinging at strike pitches and having good results."

Cubs starter Edwin Jackson allowed two runs, one earned, and two hits in 5 1-3 innings in his first start since going 8-18 last season and leading the major leagues in losses.

Pittsburgh starter Charlie Morton pitched six scoreless innings.

The Cubs' first run came when an umpire's call was reversed by video replay.

Nate Schierholtz appeared to ground into an inning-ending double play with the bases loaded. However, Renteria asked for the call to be reviewed and it was ruled that Mercer, the shortstop, came off the second base bag while taking a throw from Walker, the second baseman, which made Rizzo safe at second base.

Walker was charged with an error that enabled Bonifacio to score from third base.