Ketel Marte blasted a loud foul ball on the first pitch he saw on Friday night, a swing that might qualify as his most aggressive-looking, his most damage-seeking, in recent weeks – if not the entire season. It turned out to be a sign of what was to come.

Marte homered, doubled twice and singled in his most explosive night of the season, leading the Diamondbacks to a 6-5 win over the San Francisco Giants at Oracle Park. For the Diamondbacks, the evening was a glimpse into the past of what Marte was for them last year – and, they hope, a look at what he can be for them again.

The win snapped a five-game losing streak for the Diamondbacks, who were victorious for just the second time in their past 15 games.

The Diamondbacks, as their 15-24 record would suggest, have had a litany of problems this season. Key players have gone down with injury. Others have pitched or played their way out of roles or off the team entirely.

In light of all that has occurred, it might seem odd to suggest Marte has been an issue. But it is hard to overstate how much they have missed the hitter he was last season.

A year ago, Marte rated as one of the most impactful players in the National League. He hit .329 and slammed 32 homers. He was a force in the middle of their lineup, the kind of hitter whose transcendence on many nights helped mask the underperformance of teammates.

This year, Marte had provided them with no such coverage. Entering Friday, he was hitting .299, but had just a .335 on-base and .396 slugging. His OPS was 250 points below where it was at the end of last year.

“Anytime you have that catalyst,” Diamondbacks manager Torey Lovullo said, “that offensive catalyst that’s going be an impact guy and he’s swinging the bat good, it’s bound to make everybody better.”

Just about everyone was better for the Diamondbacks on Friday. Nick Ahmed had three hits. Christian Walker was on base three times. Rookie Daulton Varsho had two hits, including a two-run single. The Diamondbacks three hits with runners in scoring position, which is three more than they had the past four games combined.

“Those are the things we know these guys can do,” Lovullo said. “We finally got ourselves in the right frame of mind and made some good things happen.”

In a normal year, a night like this from Marte in the team’s 39th game of the season would provide hope for what might be to come, regardless of a team’s record. That is not how things feel this year, but over the final 21 games Marte can at least show that what he did last year is still in there somewhere, if only he can tap into it more often.

“I felt really good, I felt strong today,” Marte said. “Thankfully, I’ve been healthy and I felt that way today. My approach has been the same as always and that’s to try to put really good swings on the ball and have really good things happen.”

For most of the year, Marte has not looked like the aggressive, hulking power hitter he was for most of last season. At times, his timing has seemed off. Other times, he has appeared to be trying to shoot balls the other way. His swings have more often produced line drives in search of holes rather than blasts trying to carry over fences.

Marte has offered conflicting explanations to reporters about what has been behind the power outage, alternately saying he has tried to take more of a top-of-the-order/get-on-base approach before admitting he hasn’t been able to hit for the power he would like. Similarly, Lovullo defended the season Marte has had, but he also pointed to how hard Marte has worked to improve.

“He works tirelessly to make good things happen,” Lovullo said. “It was nice to see him have some good moments tonight.”