CINCINNATI -- There was plenty of frustration evident in the Pirates' clubhouse after a second consecutive extra-inning loss to the division-leading Reds. But it wasn't difficult to find the silver lining.

If Charlie Morton needed a boost of confidence to ride for the remainder of the season, he can look no further than his outing on Saturday night before a pennant-feverish crowd of 36,101 at Great American Ball Park.

But Morton's finest start of the season became a subplot when Joey Votto blasted a walk-off home run off Justin Thomas in the 10th inning to cap a 5-4 final.

Morton's performance did not go unnoticed -- and neither did the Pirates' resiliency in rallying for four runs in the eighth to briefly grab the lead after being blanked for seven innings by Reds starter Edinson Volquez.

"We did some really good things tonight," said Pirates manager John Russell. "It was really exciting. The guys have been really feeding off and doing some fun things. The next step is win."

Morton gave up three runs and six hits, walked one and struck out two. He needed just 69 pitches to get through 6 1/3 innings.

"Charlie threw the ball really well," Russell said. "It was nice to see him out there with some confidence and throwing the ball like he's capable of. He's been building toward this. Hopefully he can continue that. It was a very positive start for him."

His only rough inning was the second. Scott Rolen led off with a double and Jonny Gomes singled. Morton then hit Ramon Hernandez to load the bases before Drew Stubbs' sacrifice fly to center put the Reds ahead, 1-0.

Morton prevented further damage when Miguel Cairo grounded into a 5-4-3 double play to end the inning. He allowed only a walk and a double over the next four innings.

"I felt like myself," Morton said. "I was able to relax. The key [in the second inning] is that I wasn't worried about it. I wasn't looking ahead."

"He needs to not worry about the results and just go out and execute," Russell said prior to Saturday's game. "When he does that, he's pretty effective."

For seven innings, Morton was outdueled by Volquez, who allowed only a one-out single to Jose Tabata in the first inning before retiring the next 20 batters he faced.

"Volquez was as nasty as we've seen him," said Neil Walker. "We knew once we got him out of game we could give ourselves a shot."

Trailing by three runs in the eighth, the Pirates scored four runs on four hits to take a 4-3 lead. Walker provided the key blow when he extended his career-long hitting streak to 17 games with a two-run single off Cuban fireballer Aroldis Chapman.

"I was just trying to put a good at-bat together," Walker said. "It doesn't matter how hard you throw. This is the big leagues. We're taught to time up any pitch and put the bat on it."

Chapman took his first career blown save, but he was spared defeat when Chris Heisey's RBI double off Joel Hanrahan drove in Stubbs in the ninth to force extra innings.

"I need to execute my pitch better there," Hanrahan said. "If I get it down and away, it might be a double play and we win the game. The guys battled tonight. Getting four runs is not easy, especially on the road."

Francisco Cordero (6-4) pitched a scoreless 10th to earn the victory. Thomas (0-1) took the loss for Pittsburgh.

Votto, who was 0-for-2 with a walk against Morton, finished off a frustrating night with his 33rd home run and first career walk-off homer.

"This game will get you sometimes," Votto said. "I was frustrated, but I try my very best to not take it to my next at-bat. I feel like I did a good job of that. I didn't let it carry over."

The Pirates are 4-7 in extra-inning games this season.

"We did a lot of good things tonight," Walker said. "But you've got to tip your cap to the Reds. They're in first place for a reason."