The LG Twins are moving on to the second round in the Korea Baseball Organization postseason.

The Twins rallied to defeat the Nexen Heroes 5-4 to take the best-of-five first round series in four games at Jamsil Stadium in Seoul. Shortstop Oh Ji-hwan broke the 4-4 tie with a single in the eighth, completing the Twins' comeback from a 4-0 deficit, and the shutdown bullpen picked up the slack after a shaky start by Ryu Jae-kuk.

The Twins will next face the NC Dinos, who finished second in the regular season and had the bye to the second round.

The Dinos have the home field advantage. Their series opens Friday at Masan Stadium in Changwon, South Gyeongsang Province, some 400 kilometers southeast of Seoul.

The Heroes' offense, which had batted .179 (5-for-28) with runners in scoring position in the series before Monday, came to life with four runs in the second inning against Ryu.

With men at first and second, Lee Taek-keun hit an RBI single up the middle. The Heroes then added a run on a bizarre play.

Park Dong-won sent a chopper into the hole between third and shortstop, and Oh, trying to make a play on the run, instead knocked the ball into foul territory, allowing Kim Min-sung to score from second.

Two batters later, Seo Geon-chang drove in two more runs with a single to right.

Ryu lasted just two innings, after giving up four runs on four hits. It was the shortest outing by any starting pitcher in six games so far this postseason.

The Heroes appeared to be in cruise control, but Oh delivered an RBI single off starter Scott McGregor in the bottom third to cut the deficit to 4-1.

The Twins scored their second run in the third thanks to an error and heads-up baserunning. With men at first and second, Nexen shortstop Kim Ha-seong grabbed a grounder up the middle and tried to get the force at second. But his toss to second baseman Seo Geon-chang was too high, and as Seo dropped the ball, Luis Jimenez, who'd moved to third on the play, sprinted home to score without a throw.

The Twins erased the deficit in the two-run fifth.

They loaded the bases with three consecutive singles in the bottom fifth, with McGregor leaving the game after the second of those hits.

Facing new pitcher Kim Sang-su, Chae Eun-seong hit a foul fly to first, but first baseman Yoon Suk-min dropped the ball in what should have been the inning's first out.

After the error, Kim hit Chae in the arm to let in a run.

Yang Suk-hwan then hit a sharp grounder to short, and the only play shortstop Kim Ha-seong had was to get the force at second, with Jimenez scoring from third.

The Twins couldn't cash in after the first two batters of the sixth reached with singles and also failed to capitalize on a one-out single in the seventh.

But in the eighth, they drew back-to-back one-out walks from Nexen closer Kim Se-hyun. Cleanup Jimenez flied out to left, but Oh stepped up and dumped a single to shallow right to put the Twins ahead 5-4.

Oh went 4-for-5 with two RBIs to more than atone for his earlier defensive mishap.

After Ryu's departure, the Twins' bullpen blanked the Heroes and kept the team in the game long enough for the final rally.

Lee Dong-hyun, Yoon Ji-woong and Kim Ji-yong sat down 11 straight batters at one point, as they combined for 4 2/3 shutout innings. Jin Hae-soo, Jeong Chan-heon -- the winning pitcher -- and closer Lim Jung-woo got the final seven outs to complete the clinching victory.

LG manager Yang Sang-moon credited the bullpen with keeping the team in the game.

"Our starters had pitched deep into earlier games," Yang said.

"And I felt our bullpen guys would be ready to get the job done today."

The Twins climbed from eighth among 10 clubs at the All-Star break to fourth at the end of the season, and had to get past the wild card series against the Kia Tigers to take on the Heroes.

They then dispatched the Heroes in four games, but Yang admitted he hadn't thought much about the next series.

"To be honest, I am not really prepared (for the next round),"

Yang said with a smile. "So I don't really have much to say at this point."

McGregor, pitching on three days' rest, couldn't get out of the fifth inning after giving up back-to-back singles to start the inning. He was charged with three earned runs on nine hits in four innings.

Kim Se-hyun, who led the regular season with 36 saves, took the loss. (Yonhap)