Vasek Pospisil and Milos Raonic opened the best-of-five series with a pair of convincing wins at Uniprix Stadium on Friday as Canada took a commanding 2-0 lead.
"We won six sets in a row and Vasek did well, coming out first," Canadian captain Martin Laurendeau said. "His outing in Vancouver (against France) was a long time ago. He was anxious to get back, have a great performance to get us a win and he did that really well. He set the tone and Milos backed it up."
Pospisil beat Izak van der Merwe 6-3, 6-4, 6-4 in the first match of the afternoon against injury-riddled South Africa. The visitors were missing their highest-ranked player in Kevin Anderson (37th in the world) and saw Rik de Voest withdraw this week with a wrist injury.
Pospisil had seven aces and broke van der Merwe four times.
"It feels great, it feels incredible. I was obviously really, really happy to get through it," said Pospisil, of Vancouver. "These were really important matches for me. The Davis Cup is a lot of pressure, a lot of expectation and I care a lot about it so I really wanted to win, get that first match."
Raonic followed that up by defeating Nikala Scholtz, who was playing in place of de Voest, 7-5, 6-4, 7-5.
"I was very proud of Nik. I thought he did really well. To step up and play for your country on a big stage like this against someone who is top-15 in the world, there's a lot of guys that have frozen," said South Africa captain John Laffnie de Jager. "He came out and the longer the match went on, the more it looked like he felt he belonged there."
Pospisil jumped out to a 2-0 lead in his opening set but van der Merwe rallied to tie it 2-2.
The sixth game would prove to be a turning point. Ahead 3-2 but trailing 40-0, Pospisil fought back to take a two-game lead.
He found his groove in the third set, jumping out a 3-1 advantage. Van der Merwe twice inched within a game but Pospisil held his ground.
Making quick work of his opponent was important for Pospisil, who will be back on the court on Saturday afternoon with Daniel Nestor for the doubles match.
"Obviously it's great for me. When you have momentum like two sets-love you don't want to let the guy have a sniff at coming back," Pospisil said. "Those matches can shift momentum. Even if you're up two sets and you're in a great position, you lose that third set and maybe he starts to believe a little bit.
"I was really happy to break in that third set, win in three straight and get some rest for tomorrow."
Raonic, who is ranked 15th in the world, recorded 26 aces on the afternoon. His renowned serves gave him the edge, earning 17 points off his 28 second attempts.
"I always say, you determine who has the best serve by the guy who has the biggest second serve. (Milos) was serving 220-224 (kilometres per hour) second serves," de Jager said. "He's got unbelievable variety on his second serve and he follows it up with a big forehand."
Raonic, of Thornhill, Ont., and Scholtz each held serve in the opening set until the Canadian broke Scholtz to go ahead 6-5.
"I was a little bit disappointed not to get breaks earlier but at the same time, I was holding pretty comfortably so I knew it was just a matter of time before I got ahead," Raonic said.
The 21-year-old dominated early in the second set but Scholtz made it interesting when he closed the gap to 5-4 and appeared on the verge of tying things up by taking a 30-0 lead. But Raonic rallied for four straight points to take the set 6-4.
The players each held serve in the third set until Raonic broke Scholtz at 5-5 to secure the win.
For Scholtz, in his second year playing for the University of Mississippi, the opportunity to play in his first Davis Cup against a player of Raonic's calibre was one he won't soon forget.
"Unbelievable, a great experience. Maybe one of the biggest days of my life," he said. "All credit to him, he's a great player. Definitely the biggest server I've ever played against and might even ever play against."
Canada needs just one more match win among the remaining three to secure its spot in the World Group. And while the task appears daunting, South Africa hasn't lost any hope.
"The tie's not over. A lot of teams have come back," de Jager said. "Our focus needs to be to get that one point tomorrow in the doubles and keep the tie alive, and then try to see what we can do Sunday."