Canada's Vasek Pospisil eyes the ball before returning it to Ecuador's Ivan Endara in their Davis Cup match on Friday. ((Patricio Realpe/Associated Press))

Canada trails Ecuador 2-0 at the Davis Cup on Friday after the first day of action in the Americas Zone Group I second round tie.

Vasek Pospisil of Vernon, B.C., dropped the opening singles match to Ivan Endara 6-3, 6-4, 6-7 (6), 6-3, while Vancouver's Philip Bester was unable to even the score, falling to Julio-Cesar Campozano 7-6 (4), 6-7 (4), 7-5, 6-2 in the evening's second pairing.

"Davis Cup is so unpredictable with varying conditions and boisterous crowds often playing a huge role and rankings really go right out the window," said Canada's team captain Martin Laurendeau. "We are obviously in a tough position now, but we have come back from this before and we will come out tomorrow, take it one match at a time and try to claw our way back into it."

Canada needs to win all three remaining matches in the best-of-five series to claim victory over Ecuador.

A win over Ecuador will advance the Canadian squad to a World Group playoff in September while a loss will keep them in the Americas Zone Group I for 2012.

After going down 3-0 to start the match, Pospisil regained some composure and started to hold serve on the clay court. It looked as though he had turned it around after saving a match point, winning the third set in a tiebreak and going up a break 3-1 in the fourth, but Endara stormed back to win five straight games and the match.

"I'm disappointed that I wasn't able to get the win today but I had some good moments and we have practiced a lot this week on the clay so I'm getting more and more comfortable with the conditions," said Pospisil, who was playing in his first Davis Cup singles match.

"I'm looking forward to coming out again tomorrow in doubles and trying to secure that crucial point for the team."

Pospisil is the highest-ranked singles player in the tie at No. 191.

It was then up to Bester, in his first Davis Cup action since 2006, to try and even the score.

He squandered two set points at 6-5 and went on to lose a tough tiebreak. The match remained tight throughout, with Bester taking another tiebreak in the second set. A break late in the third restored Campozano's lead.

Bester, ranked No. 229 on the ATP Tour, was unable to recover in the fourth set ceding the second point of the day to the opposition.

Play continues Saturday with doubles play as Pospisil and Toronto's Daniel Nestor — ranked No. 4 in the world in doubles — will take on Ecuador's duo of Roberto Quiroz and Emilio Gomez.

Sunday will have the reverse singles with Pospisil playing Campozano and Bester facing Endara.

Team captains may substitute their players up to an hour prior to the start of the match. Peter Polansky of Thornhill, Ont., is the fourth member of Canada's Davis Cup squad.

Milos Raonic, also from Thornhill, was unable to play for Canada after having hip surgery on July 5. The No. 26 singles player in the world — and Canada's highest-ranked player — injured himself at Wimbledon.