LOS ANGELES (Interstat) — Pinch-hitter Patrick Bailey had a tying RBI double during San Francisco’s three-run rally in the eighth inning, and the Giants battered Los Angeles Dodgers reliever Blake Treinen to avoid a four-game series sweep with a 3-1 victory on Sunday evening.

The struggling Treinen (1-7) dramatically blew a 1-0 lead in the eighth, allowing three runs on three hits and two walks while facing only seven batters. Incredibly, Treinen took his fifth loss in his last seven appearances despite pitching just 5 1/3 innings in that stretch. The 37-year-old Treinen was a big contributor to the Dodgers’ championship run last season, but his latest in a series of disastrous outings ballooned his ERA to 5.55.

The defending World Series champions’ bullpen has largely struggled for weeks, playing a major role in the team’s inability to avoid a wild-card playoff series.

For seven innings, the game was a masterful pitchers’ duel dominated by Dodgers starter Emmet Sheehan. The right-hander was brilliant, tossing seven shutout innings and allowing just one hit while striking out 10. He retired 20 of the 21 batters he faced, with the only blemish a first-inning single by Rafael Devers.

Giants starter Trevor McDonald nearly matched him zero for zero. McDonald allowed one run on six hits over six innings, striking out three. The Dodgers finally broke through against him in the seventh.

Max Muncy walked and Andy Pages singled to put two on with no outs. Michael Conforto then delivered a sharp line drive single to left field, scoring Muncy to give the Dodgers a 1-0 lead. A sacrifice bunt moved the runners to second and third, but the inning ended abruptly when Tommy Edman lined into an inning-ending double play, stranding two runners.

Sheehan’s dominant afternoon ended after the seventh, turning the one-run lead over to the bullpen. Treinen entered and immediately ran into trouble.

Christian Koss led off the eighth with a single and Drew Gilbert followed with another single, putting runners on the corners. Bailey, pinch-hitting for Andrew Knizner, then ripped a ground-rule double down the right-field line, scoring Koss to tie the game 1-1.

After a flyout, Treinen intentionally walked Devers to load the bases. Willy Adames then worked a full-count walk to force in Gilbert, giving the Giants a 2-1 lead. Matt Chapman followed with a soft groundout to shortstop, but it was enough to score Bailey from third to extend the lead to 3-1.

Spencer Bivens (4-3) got the win with a scoreless inning of relief. Ryan Walker recorded the final two outs in the ninth for his 16th save, striking out Michael Conforto to end the game.

The Giants managed just five hits but made them count in the decisive eighth. The Dodgers collected seven hits but went 1 for 7 with runners in scoring position and left six men on base.

The game was played in a swift 2 hours, 27 minutes in front of an announced crowd of 46,601 at Dodger Stadium.

With the win, the Giants improved to 77-79, avoiding falling to .500 for the first time since August. The Dodgers fell to 88-68. San Francisco travels home to open a three-game series against the St. Louis Cardinals on Monday. The Dodgers have a day off before beginning a three-game road series against the Arizona Diamondbacks on Tuesday.