Merrill Kelly's vintage start helps D-backs split Padres series

Merrill Kelly delivered a vintage seven-inning start Thursday night, allowing one run on three hits as the Arizona Diamondbacks beat the San Diego Padres 3-1 at Petco Park. The win secured a 2-2 split in the four-game series and offered a glimpse of the steady Merrill Kelly Arizona has relied on for nearly a decade.

After a brutal middle stretch of the Padres set, the Diamondbacks needed their veteran right-hander to look like himself again. He did — and just in time.

Key Takeaways

• Merrill Kelly allowed one run over seven innings with six strikeouts and three walks, his second straight start with two or fewer runs allowed.
• Arizona beat San Diego 3-1 to split the four-game series 2-2 and pull even with the Padres in the NL West standings.
• Nolan Arenado's sixth-inning homer and Geraldo Perdomo's RBI single supplied the offense behind Kelly's gem.
• Kevin Ginkel and Paul Sewald closed out a combined three-hitter with perfect relief innings.
• The Diamondbacks remain 5.5 games back of the final Wild Card spot, but avoided a worse result against a division rival.

Why did Merrill Kelly's start matter so much for Arizona?

The 2026 season has been a grind for Kelly. After re-signing with the Diamondbacks as a free agent this past offseason, he was named the team's Opening Day starter only to suffer an injury during Spring Training that caused him to miss the first few weeks of the regular season.

Kelly has long been a consistent member of the rotation, but that had not been the case this year. Entering Thursday, his ERA sat at 5.71 across 15 starts, a far cry from the dependable arm Arizona has leaned on for nearly a decade.

For the second straight outing, Kelly looked more like the Merrill Kelly the Diamondbacks have grown accustomed to seeing. Mixing up his pitches, he kept the Padres' hitters off balance during his seven innings of work. It was more of the same after he showed some of his old form against the Milwaukee Brewers in his previous start.

With two teams battling to stay alive in the Wild Card race and hoping to be buyers at the 2026 Trade Deadline, Arizona could not have afforded worse than a split. Though the Diamondbacks could not come away with a series win, they held their own against their NL West rival.

How did the Diamondbacks scratch across enough runs to win?

Offense has not always been the story for Arizona in 2026, but the Diamondbacks did just enough on Thursday night. San Diego starter Griffin Canning (1-7) was chased in the fifth after allowing the go-ahead run.

A wild pitch by Canning brought in Arizona's first run in the fourth inning. Geraldo Perdomo's RBI single with two outs in the fifth gave the Diamondbacks a 2-1 lead and ended Canning's night.

Nolan Arenado delivered the insurance. He homered to left field off Yuki Matsui with two outs in the sixth, his 11th of the season and 364th of his 14-year career. Arenado is now six hits shy of becoming the sixth active player to reach 2,000 hits.

The Southern California native has been dangerous at Petco Park throughout his career. He has 17 homers at the downtown ballpark, the most by a visiting player, and has reached base safely in 25 of his last 26 games there since Sept. 1, 2018.

What happened on the mound beyond Kelly's line?

Kelly's only big mistake was allowing Manny Machado's solo homer to right leading off the second inning. It was Machado's 19th home run of the season and his fifth in 11 games. Machado was back in the lineup after sitting out Wednesday, a night after fouling a ball off his left big toe.

Beyond that blast, Kelly quieted the Padres a night after they rolled to a 10-4 victory. He held San Diego to one run and three hits in seven innings, with six strikeouts and three walks. Kevin Ginkel pitched a perfect eighth inning, and Paul Sewald worked a perfect ninth for his 21st save.

According to Sports Illustrated, Kelly landed 55 of his 94 pitches for strikes and collected 12 whiffs and 16 called strikes — encouraging signs that his stuff was moving. The outing may have been one of the best Merrill Kelly performances of the year, barring his complete game in Colorado.

For a deeper look at how veteran arms can recapture their old form, see our Nostalgia: Then & Now coverage.

Has Merrill Kelly turned a corner in 2026?

That is the big question Arizona now faces. Kelly's ERA dropped to 5.38 after Thursday's outing, but he still has had success only in small bursts this season. It has been ugly overall, and the Padres offense had been slumping before this series.

Still, two consecutive strong starts are hard to ignore. Kelly allowed two or fewer runs in each of his last two outings, including five innings against Milwaukee on July 4 when the only damage was a two-run homer by Christian Yelich. Against San Diego, he went deeper and looked sharper doing it.

As MLB.com reported, the right-hander finally appeared to be pitching with the confidence that made him a rotation staple. Whether that becomes a lasting turnaround or a brief flash remains to be seen.

What does the Padres series split mean for the playoff picture?

The Diamondbacks improved to 46-47 with the win. They are not exactly roaring toward the All-Star Break, trade deadline, and eventual postseason, but they are currently in a dead-even split with San Diego for the season series. Making sure this four-game set was, at worst, a 2-2 split was important.

Arizona is still a ways out of a playoff spot. The Diamondbacks are 5.5 games back of the final Wild Card, with four teams ahead of them. But for now, they pull even with the Padres, who could be in that late-season race regardless of their current struggles.

Both clubs entered the week jockeying for second place in the NL West, well behind the two-time defending champion Los Angeles Dodgers. Arizona popped back into a tie with San Diego, 14 1/2 games behind the idle Dodgers.

This series will not be the final time the Diamondbacks and Padres match up this season, but losing too many first-half games to teams of similar records and in the same division can tend to haunt playoff hopefuls as the postseason nears. The Diamondbacks know this all too well.

Meanwhile, the rotation picture remains uneven. Zac Gallen is still searching for answers after surrendering a four-run first inning in game two of the series. The fact that Gallen tossed five scoreless innings following that ugly first shows there is some capability left, though the inability to hold a lead and the big inning issue remain.

For Thursday night, though, the story was Merrill Kelly — vintage stuff, timely hitting, and a split that kept Arizona's season from slipping further at Petco Park.