Luebke, who was the Padres' supplemental first-round pick (63rd overall) out of Ohio State in 2007, walked one in the gem and struck out 10 before San Francisco relief prospect Geno Espineli came on for the final 1 1/3 innings, striking out one.
The mound dominance was nothing new for Luebke, who was one of the Padres' top Minor League pitchers this season. He combined between Advanced A Lake Elsinore and Double-A San Antonio to go 11-4 with a 2.78 ERA, striking out 112 in 129 2/3 innings. He also tossed eight innings of one-hit shutout ball back on May 24.
The U.S. team got on the board right away against veteran Canadian pitcher Chris Begg, scoring four runs in the first and never looking back.
After Buck Coats (Toronto) and Trevor Plouffe (Minnesota) drew back-to-back walks to get things started and Texas prospect Justin Smoak singled to load the bases, veteran right fielder Josh Kroeger (White Sox) drove in the first run with a fielder's choice.
DH Terry Tiffee (Philadelphia) followed with a two-run double, one of three hits he'd have on the day, and Tampa Bay veteran Jon Weber followed with another run-scoring double. Weber would also finished the day 3-for-4 with three RBIs.
The team added two more runs in the third on a pair of RBI singles from Tiffee and Weber, while Weber would make it 7-0 in the fifth with another RBI single.
Team USA capped the scoring in the seventh when Pittsburgh's top prospect, third baseman Pedro Alvarez, hit the game's only homer, a solo shot to make it 8-0.
Canada collected its lone hit with two outs in the eighth as Cubs catching prospect Chris Robinson singled to center, which marked the end of the day for Luebke, who may have gone a little longer than planned to allow him that chance at history.
In other second-round games played Sunday at various cities throughout Italy and the Netherlands:
Puerto Rico beat Spain, 12-2. Washington pitching prospect Luis Atilano got the win, allowing two runs in five innings, while Mariners veteran infielder Alex Cintron was 2-for-4 with two RBIs.
Australia finished off the Netherland Antilles, 19-6, in seven innings due to the mercy rule. Mets first base prospect Stefan Welch had a homer and five RBIs while two Phillies prospects, right fielder Tim Kennelly and catcher Joel Naughton, each had four hits on the day.
Netherlands beat South Korea, 4-2, using many top players from Curacao which left that country's Netherlands Antilles team a little short-handed. The winners got two hits each from veterans Randall Simon and Sharlon Schoop, while catcher Sidney deJong hit a three-run homer.
Cuba shut out Great Britain, 6-0; Venezuela edged Nicaragua, 7-4; Chinese Taipei beat Italy, 5-2; and Japan ousted Mexico, 9-3.
The second round of play, featuring the 16 teams that made it through the opening round, will continue through Sept. 20, leading up the to the final round, Sept. 22-27, in Italy.
The initial rosters of the 20 teams involved in the event boasted a World Cup record of more than 100 current pro ballplayers who are not on their teams' 25-man rosters, as well as several former MLB-affiliated players and professionals from other non-U.S.-based leagues.
Lisa Winston is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.