The Newfoundland and Labrador skip and vice appear to have regained the relationship that made them Olympic gold medallists, as well as perennial Brier contenders prior to a split almost four years ago.
"The chemistry and how we work together and grind out games, it's been great," Gushue said. "Having a guy that's been through the battles I've been through, it's nice to have someone you can talk to or rely on in the middle of a key situation."
Gushue and Brad Jacobs of Northern Ontario opened the Tim Hortons Brier with three straight wins to top the standings Sunday. Ontario's Mark Kean, Saskatchewan's Steve Laycock and Prince Edward Island's Adam Casey were tied at 2-1.
The six teams at 1-2 were B.C.'s Jim Cotter, New Brunswick's Jeremy Mallais, Alberta's Kevin Koe, Team Canada's John Morris, Quebec's Jean-Michel Menard and Manitoba's Reid Carruthers. Jamie Koe of Northwest Territories was 0-3.
The top four teams advance to playoffs and the winner will be crowned Sunday.
During the first 13 years Nichols threw third stones for Gushue, they won gold in Turin, Italy, in 2006 with Russ Howard and Jamie Korab. They made the Brier playoffs six of eight years and lost in the final in 2007.
When Nichols relocated to Winnipeg and joined Jeff Stoughton's rink following the 2011-12 season, it created a significant void for Gushue.
His round-robin winning percentage at the Brier with Nichols was .651 compared to .545 the last three years when his teams made the playoffs once.
Newfoundland and Labrador has a smaller pool of curlers than the powerhouse provinces. Gushue recruits outside his borders. Geography makes recruiting and retaining those players challenging, so Gushue has a reputation for cycling through teammates.
Expecting their first child last year, Nichols and his wife Colette returned to Newfoundland to be closer to their families.
"He gave me a call, but I definitely was going to reach out to him," Gushue said. "It was a pretty mutual and easy decision."
It meant jettisoning second Adam Casey, now P.E.I.'s skip, and bumping Brett Gallant from vice to second.
"Having the opportunity to bring Mark back I felt was going to make our team better," Gushue said. "It was a decision that was easy but hard to let Adam know he wasn't going to be playing with us this year."
Results followed the reunification of Gushue, 34, and Nichols, 35. The team ranks second on the World Curling Tour's money list this season with a record of 42-18. They've won two Grand Slams this winter — the National and the Masters.
"It was pretty seamless to move back into this position and come onto the team," Nichols said. "It's been a great year.
"There's been times when we don't feel like we're playing as well as we could, but we're finding ways to win, which is something our teams in the past didn't quite do."
Gushue feels Nichols' experience is an asset when it comes to communicating with his front end. Gallant is 25 and lead Geoff Walker is 29.
"Down at the other end, he can talk to them and keep them settled in and calm in big situations in a game," Gushue said. "Having that experience back that we've lacked the last couple of years, sometimes it felt pretty lonely out there."
Whether Gushue can follow up the Olympic gold he won at 26 with a Canadian title is now a constant subplot at the Brier.
"I really feel that this team, if it plays anywhere close to our ability we'll be there come Sunday," Gushue said.
Gushue scored wins of 8-5 win over Northwest Territories and 9-7 over Team Canada, while Jacobs downed B.C. 7-5 and Alberta 9-5 on Sunday. Jacobs won both Canadian and world titles in 2013 before winning Olympic gold in 2014.
"We're playing decent. There's lots of room for improvement," the Northern Ontario skip said. "We're not quite as consistent as we want to be, but we're only three games in. We've played well enough to win and that's all that matters."
Alberta and Team Canada, both skipped by Calgarians, had shaky starts although Alberta's Koe rebounded Sunday night with a 7-3 win over Ontario.
Also in the evening draw, Saskatchewan downed Northwest Territories 10-6, Manitoba picked up its first win in a 9-5 decision against New Brunswick and P.E.I. won 6-5 over B.C.
Koe revealed he was struck with a stomach flu just prior to Alberta's first game. His shooting percentage over their first two losses was just 66 per cent, while his teammates were all plus-90. Koe upped his accuracy versus Ontario to 93 per cent.
"Luckily we bounced back with a big win tonight. We needed it," Koe said. "We're not used to losing a bunch in a row. It's nice to win some for the fans too."
Morris lost twice Sunday, including a 7-4 loss to Casey.
"We're probably playing 80 per cent curling and 80 per cent will get you a .500 record at the Brier," Morris said. "We need to boost it up a bit. Tough day for us."
Attendance was down significantly on opening weekend from 2009 when the Brier was last held at Scotiabank Saddledome. After five draws, attendance was 33,081 compared to 65,000 six years ago.