Koevermans scored twice, Frings bolstered the central defence in his sweeper role and Toronto FC got big assists from Ashtone Morgan, Nick Soolsma and Richard Eckersley in a 2-1 win over the MLS champion Colorado Rapids.
Morgan and Soolsma set up Koevermans' goals with crosses while Eckersley preserved the win with a 90th-minute goalline clearance.
"I think we earned it today," said Toronto coach Aron Winter, happy to put an ugly 4-0 midweek loss to Mexico's Pumas in CONCACAF Champions League play behind him.
Koevermans, an imposing six-foot-three Dutch striker, has scored goals but been frustrated by minor injuries since making his debut with Frings in mid-July.
He twisted his ankle during a CONCACAF Champions League game in Panama and "then everything was sore in my whole body."
He also attributes the body breakdown to joining MLS in mid-season.
"That makes it even more difficult, especially for Torsten and me," he said. "Because you come in a league that continues. Everybody's fit and everybody's strong here, everybody's quick. And we had our holiday. We got in with just five or six days training and we started (playing)."
Frings, meanwhile, moved back from his midfield general role to marshall the Toronto defence. When Colorado had the ball, he drifted back into a five-man backline between central defenders Andy Iro and Ty Harden. When Toronto got possession, he crept up a little but still looked to defend, freeing up fullbacks Morgan and Eckersley to maraud down the wings.
After a drab first half that saw the crowd of 20,318 in a near comatose condition on a breezy afternoon at BMO Field, Koevermans triggered some excitement with two goals in eight minutes.
The game came alive in the 52nd minute when Toronto's Eric Avila found Morgan alone on the left. The 20-year-old Canadian fullback then sent a precise, raking cross through the penalty box that Koevermans tapped in.
The Dutch forward made it 2-0 eight minutes later with a beautiful glancing header off a cross from the right from Soolsma.
"Great goals," said Winter.
The second showed Koeverman's predator-like skills in front of goal as he bent his long body into a position to nod the ball into the net.
Gambian striker Sanna Nyassi pulled one back for the Rapids in the 70th, burying a ball high in the net from close range after a frantic attack that saw Morgan stop a shot with his face.
The home side had some rocky moments in the final minutes but hung on for the win. Eckersley preserved the win with a goalline clearance in the 90th minute, with goalie Milos Kocic sprawled helplessly in front of him.
"The goals were good finishes from Koevermans, of course," said Colorado coach Gary Smith. "But the crosses were too easy to get in. Defensively we're simply better than that."
Toronto (6-12-12) is now unbeaten in three league games while Colorado (10-9-11) has lost three straight and is winless in four.
Smith acknowledges it's made for a dip in confidence.
"We're actually in an encouraging position in the league, but finding those last couple of victories that are going to nail down a post-season spot are proving to be quite tough."
Smith reckons his team will need two more wins — from remaining home games against San Jose, FC Dallas and Real Salt Lake and the season finale in Vancouver — to secure a wild-card spot.
Koevermans, one of Toronto's three designated players, now has six goals in seven games this season. He came off to applause in the 73rd minute and later pronounced that he felt good.
"It's a pleasure when you score two goals," he said. "You feel the pain less."
But he wasn't about to pick one goal over another.
"If I score with a goal with my little toe or a rebound on the line that goes in, I don't mind. It feels good to score however I make it."
It was the third game in a week for both teams (three in eight days for Colorado) — with Toronto squeezing in a trip to Mexico along the way — and it showed early on.
The first half was lacklustre, before a muted crowd. Toronto's normally frenetic fans in the southeast corner stood silent as their team failed to put a shot on target in the first 45 minutes. They finally found their voice in the second half, thanks to Koevermans.
The Rapids won the MLS Cup at BMO Field last year but have been average this year in a season that featured six straight ties in one stretchey came into Saturday's game having been shut out by Los Angeles and Chicago in their last two outings.
Both teams suffered heavy midweek defeats by Mexican sides in the CONCACAF Champions League — Toronto 4-0 at Pumas and Colorado 4-1 to visiting Santos Laguna.
Toronto has leaked goals all season with a league-worst 52 goals against and 32 goals for. The good news is that Toronto has scored 13 times in its last seven games — a 3-1-3 stretch.