That run came to an end on Wednesday night, and the Reds were playing from second place again with just four games left before the All-Star break.
But struggles heading into the break are nothing new for Cincinnati. In 2010, the Reds were swept in four games by the Phillies heading into the break.
Last year, the first half ended with the Reds losing three of four to Brewers, all by one run.
The Padres faced similar struggles last season, dropping their last five before the break, all against fellow West Coast teams.
The Reds are now in the position the Padres were, ending the first half of the season on an 11-game West Coast road trip. Heading into Friday's contest, the Reds boasted a 3-5 record with three games remaining before the break.
"It's always been tough for us on the West Coast," said Reds pitcher Bronson Arroyo, who will make the start Friday at Petco Park in the second game of a four-game series.
Arroyo (3-5, 4.06 ERA) struggled in his most recent outing last Sunday at San Francisco, failing to take command and running his pitch count to 113 in just six innings.
He gave up two runs on seven hits for his eighth no-decision of the year.
He'll face off against former Reds teammate Kip Wells, who made a short stop in Cincinnati in 2009, making 10 appearances, including seven starts, with a 2-3 record. They were his last Major League appearances until joining the Padres this year.
It will mark the third straight former Reds starting pitcher Cincinnati will face, after battling Aaron Harang on Wednesday in Los Angeles and Edinson Volquez on Thursday night.
In May, Wells (1-1, 1.50 ERA) agreed to a Minor League contract with San Diego and was called up in late June to make his first start since 2009.
He earned his first win in three years in his most recent outing, shutting out the Rockies over seven innings, allowing six hits. It was the first time since 2007 that Wells pitched seven shutout innings.
"You make your own luck," Wells said. "Good things happen for opportunistic people. I got balls hit at people when I needed it and the balls hit in the air hung up. I tried to get quick outs and not pitch too fine to where I'm falling behind in the counts."
Reds: Offensive struggles continue
The typically hot Reds bats have been quiet recently.
The Reds scored the fifth-most runs (127) in the Major Leagues in June, but have struggled in the new month.
After dropping eight runs on the Dodgers on Monday, the Reds have had three straight one-run outings, tarnishing three stellar outings from Reds' starting pitchers.
"We have to capitalize whenever we have the opportunity," said Reds' manager Dusty Baker.
Reds third baseman Scott Rolen's status continued to improve Thursday, and it's unlikely the 37-year-old veteran will be placed on the disabled list.
Rolen has not played since last Friday, battling back spasms for six games, but said he ran sprints and lifted weights Thursday and is on the road to recovery.
"I don't want to go on the DL. I'm hoping that's off the table," Rolen said. "I plan on being available [Friday] for sure. My activity level went up."
Rolen has played in 41 games this year and is batting .184.
Padres: Injuries mount for starting pitchers
San Diego can't seem to catch a break with its starting pitchers.
The Padres currently have seven starters on the disabled list and added more bad news Thursday, as Joe Wieland had a setback in his recovery from his strained right elbow.
Wieland's throwing program was halted recently after sharp pain in his right elbow returned.
"It's frustrating," Padres manager Bud Black said. "Once you think you have things back on track and things look to be going in the right direction as far as guys rehabbing, getting Cash back, Joe was progressing, [then] to have a couple setbacks like we did ... it's frustrating."
Wieland, who has been on the disabled list since May 7, had been making steady progress in his recovery before the pain in his elbow began.
Wieland's news comes just two days after Andrew Cashner left his start Tuesday in Arizona with a strained lat muscle.
Cashner was placed on the DL on Wednesday, and plans to have an MRI on Friday.
"It's frustrating, because you want guys to pitch, and so do they," Black said. "Players want to play. It's frustrating in so many ways. At the same time, you're in this game a long time [and] you realize these things happen.We just hope that this is one of those years where the extraordinary amount of injuries ... it just can't happen again. It can't happen again next year."
With their win Thursday, the Padres extended their winning streak to a season-best six games.