By Martyn Herman
MADRID (Reuters) - Canada became the first nation to reach the quarter-finals of the revamped Davis Cup as they beat the United States for the first time at the 16th attempt on Tuesday.
For the second day in a row 150th-ranked Vasek Pospisil gave them the perfect start before 20-year-old Denis Shapovalov finished the job to make it two wins from two in Group F.
Pospisil, who upset the rankings to beat Italy's Fabio Fognini in their opening tie, edged out towering American youngster Reilly Opelka 7-6(5) 7-6(7) to the delight of a vocal Canadian contingent in the stands.
Shapovalov, who reached the Paris Masters final this month and has risen to 15th in the rankings, then beat Taylor Fritz 7-6 6-3 to seal the win.
Oddly the doubles rubber was conceded by the Canadians as three of their players were declared unfit to play, according to an ITF spokesman, so the final result was 2-1 to Canada, the same scoreline by which they beat Italy by Monday.
"USA will get one match win and a 6-0 6-0 scoreline in terms of sets and games won. If Italy defeats U.S., it will have no impact at all," the ITF said in a statement.
The 18 nations taking part at La Caja Magica are split into six groups with the group winners and two best runners-up moving through to the quarter-finals on Thursday and Friday.
Tuesday's clash was the first between the north American neighbours since 1965. Canada had lost the last four meetings, all played under the old five-rubber system, 5-0.
The U.S. have won a record 32 Davis Cups but not since 2007.
(Reporting by Martyn Herman; Editing by Toby Davis and Ken Ferris)