(Photo credit: Aaron Doster-Imagn Images)

The San Francisco Giants will try to accomplish a couple of firsts for this season in the series finale at the Washington Nationals on Sunday.

The Giants will look to win four consecutive games for the first time and will also try to complete their initial three-game series sweep.

Both are possible because the Giants outlasted the Nationals 7-6 in 12 innings after watching the Nationals tie it in the ninth on Saturday.

A pair of veterans match up in the finale when San Francisco left-hander Robbie Ray (2-2, 2.42 ERA) opposes right-hander Miles Mikolas (0-3, 11.49).

Ray has given up two earned runs or fewer in each of his four starts. On Tuesday, he allowed two runs on two hits and four walks in a loss to the Cincinnati Reds.

'I felt good,' Ray said. 'I felt like the fastball and the changeup were working good. Slider was playing really well. Struggled a little bit with the curveball ... that's something I'm going to work on a little bit going into my next outing.'

He is 3-5 with a 5.21 ERA in nine starts against the Nationals.

Mikolas has struggled, allowing 20 earned runs in 15 2/3 innings. On Tuesday, he gave up three runs on three hits in 3 1/3 innings working behind an opener.

He is 5-1 with a 3.20 ERA in 10 games (six starts) versus the Giants.

The Giants rallied from a 5-1 deficit on Saturday, took the lead in the seventh, surrendered it in the ninth and won it in the 12th.

'That was one where the baseball gods didn't feel like they were going to let us lose today,' manager Tony Vitello said. 'There were several moments where we could have lost that game. I'm sure they could say the same in the other locker room. That's what made it a great, March Madness, playoff-type game.'

Heliot Ramos had three hits, including his second home run in two games. Five players provided two hits each as part of a 16-hit attack.

Ryan Walker surrendered the lead in the ninth but pitched out of a bases-loaded, no-out jam in the 10th before Caleb Kilian pitched two innings for the win.

'That was super exciting,' Killian said of earning his first major league win in his 18th career appearance. 'Probably long overdue.'

For the Nationals, Saturday's loss was a mistake-filled effort. Miscues in the field and on the basepaths contributed to losing the early lead and later failing to pull the game out. Washington ranks near the bottom of MLB defensively with 18 errors.

'Every day we meet as a team and go through plays from the day before, plays that we did well, plays that we didn't do well, and then how we want to execute them as a team,' manager Blake Butera said. 'I think (Sunday's) meeting will just be a good bit longer than usual.'

James Wood hit his seventh home run for Washington, which fell to 1-7 at home. He has reached base safely in 12 of his last 13 games since April 5, batting .360 with nine extra-base hits (three doubles, six homers).

--Field Level Media