Team USA loaded the bases in the sixth via three hit batsmen by Taipei starter Tseng Sung Wei with two outs before Alvarez roped a double that banged the wall in rightfield to clear the bases.
The US added two more insurance runs in the bottom of the eighth as Alvarez added a RBI double and Tim Federowicz (North Carolina) came through with a sacrifice fly RBI.
Chinese Taipei took its first lead of the series in the first inning, on a RBI groundout by Kuo Chun Yu.
Taipei took advantage of a fielding error by Team USA in the fourth to plate another run on a sacrifice fly RBI by Chen Chiang Ho to make it 2-0.
US starter Ross Detwiler (Missouri State) gave up two runs, one earned, on one hit in 5.1 innings of work with three strikeouts and three walks. Tommy Hunter (Alabama) (2-0) came on in relief in the sixth and pitched 1.2 innings of one-hit scoreless ball with two strikeouts and a walk to pick up the win. He got out of a first and third situation with one out in the sixth by striking out a batter and inducing a groundout to third to keep the deficit at two.
Cole St. Clair (Rice) pitched two innings of one-hit shutout baseball and struck out the side in the ninth to pick up his first save of the summer.
Sean Doolittle (Virginia) led the US with three hits, while Alvarez had two hits and four RBI in the winning effort.
Tseng Sung Wei (0-1), a 2007 Cleveland Indians free-agent signee, held the USA scoreless for 10.2 inning through two starts before giving up the three-run double in the sixth. He was charged with the loss after giving up three runs on three hits with seven strikeouts and a walk.
The teams will take Monday off, before closing out the Durham portion of the seven game series Tuesday afternoon at 1 p.m. ET at the Durham Bulls Athletic Park
CHINESE TAIPEI 100 100 000- 230
USA 000 003 02x- 572
Wei, Chien (7), Ming (8), Wei (8) and Yi, Wei. Detwiler, Hunter (6), St. Clair (8) and Clark. W- Hunter 2-0, L- Wei 0-1. SV- St. Clair (1). HR- None