For a stitch in time or two, a Saints-49ers game seemed always to mean this much.

True, Sunday's game in the Mercedes-Benz Superdome, with the New Orleans Saints (10-2) and San Francisco 49ers (10-2) battling as each seeks the No. 1 seed for the playoffs in the NFC, is among the highest of regular-season stakes as this stage of the season.

The winner takes a one-game lead over the loser with three to play, and moves a step closer toward possibly playing all of its playoff games at home prior to Super Bowl LIV in Miami on Feb. 2, 2020, if it advances that far.

But what now is an occasional crossing of paths between teams from the NFC South (New Orleans) and West (San Francisco) divisions once was a two-games-a-season fistfight between West division combatants, with the upstart (New Orleans) looking to muscle its way to glory through an established power (San Francisco) in the midst of one of the NFL's most dominating runs.

And after they separated in realignment, with the Saints sent to their logical geographic destination, a playoff meeting between the two provided one of the most memorable postseason games in NFL history, a 36-32, Divisional game victory by San Francisco in 2012 that featured four lead changes in the final 4:02.

The emotions of rivalry that come with being division foes had cooled by the time the teams met in the playoffs, former Saints safety Roman Harper said. New Orleans and San Francisco finished the regular season with matching 13-3 records that year.

"This was just two very good teams," Harper said. "We'd had maybe a couple of games here and there in the year or so before."

The Saints had won four straight against San Francisco with Harper on the roster: 34-10 in the Superdome in 2006; 31-10 at Monster Park in '07; 31-17 in the Superdome in '08; and 25-22 at Candlestick Park in '10. But those matchups lacked the magnitude of the playoff game.

San Francisco scored the first 17 points, New Orleans answered with two touchdowns. The 49ers sandwiched a pair of field goals around a Saints field goal to take a 23-17 lead, and in the final 4:02, the teams split four touchdowns – Saints, then 49ers, Saints, then 49ers – with a failed two-point conversion (San Francisco) and a successful one (New Orleans) to account for the final score.

"That team was so good," Harper said of the Saints. "That was probably our best team, most talented team. As I look back on it, it's how many great players we had. Even better than '09 (when the Saints won the Super Bowl). But you look up, and it wasn't good enough to win it all.

"I thought we battled defensively after a rough start. I also remember (49ers safety) Donte Whitner hit (Saints running back) Pierre Thomas."

Whitner's helmet-to-helmet blow caused Thomas to fumble and knocked Thomas out of the game with a concussion.

"If that flag would have come out it would've been a different ballgame, because we obviously would not have had that first turnover," Harper said. "I remember us really battling back after being down. We went up, and they went up. And the way that game ended was very unfortunate. I had a lot of mixed emotions after that game because I feel like I left it all on the field. I came into the game with a messed up ankle; I left the plane and left the game in a walking boot, and played through that."

Harper also played through the birth of his daughter, Londyn. Hence, the mixed emotions.

"After losing a tough game like that, (learning) my daughter was born in the second quarter," he said. "Receiving those pictures and those texts right after the game, my oldest daughter being born, I remember how small really football seemed at the time. No matter how much I really missed it, it was a lot of emotions. That was a big day for me."

Prior to the playoff game, likely, the biggest games the Saints and 49ers played were in the years that the Saints were having the franchise's initial run of success, and the 49ers were in the midst of a historic run of success.

From 1987-92, when the Saints were in the NFC West, they were formidable team experiencing their first taste of success. The franchise never had had a winning season, then went 12-3 in '87, 10-6 in '88, 9-7 in '89, 8-8 in '90, 11-5 in '91 and 12-4 in '92.

From that, only the '91 team won a division title because at the same time, San Francisco went 13-2 in '87, 10-6 in '88, 14-2 in '89, 14-2 in '90, 10-6 in '91 and 14-2 in '92. From 1983-98, San Francisco had 16 straight seasons of 10 or more wins, 12 division titles and won four Super Bowls. The streak of 10-win seasons was an NFL record until New England surpassed it this year, with its 17th straight 10-win season.

But for six years during San Francisco's run, few teams played the 49ers better than the Saints, who went 3-9 against San Francisco during the stretch but had losses by scores of 24-22, 34-33, 24-20, 13-12, 16-10 and 21-20.

"That was our biggest rival," said Hall of Fame linebacker Rickey Jackson, a Saint from 1981-93. "That was the team we were trying to measure up to. They had all the talent, with (quarterback) Joe Montana and (receiver) Jerry Rice and (running back) Roger Craig. They had a great offense and they were putting points up.

"Our thing was great defense, our linebackers and all. We just knew that if we could hold that passing game and get to Joe Montana and keep them from passing the ball, we had a chance to hold them and beat them. Our whole thing was trying to make sure we got to the quarterback so he wouldn't be able to throw the ball to Jerry and them so quick.

"(San Francisco) was our biggest opponent the whole while I was here. We had respect for them. We disliked Atlanta, and Tampa. But for San Francisco, you had respect for them because you weren't beating them consistently. They were on top. They had won the Super Bowl when I got there (in New Orleans), had a great coaching staff. You couldn't hate them as much as you did Atlanta. Atlanta was more on our scale, (but) who we thought we could beat. San Francisco was somebody we were trying to overcome."

For former Saints Coach Jim Mora (1986-96), it wasn't a matter of the Saints rising to success at the wrong time, or a guarantee that there would have been success if New Orleans had been in another division.

"I don't like to think that," Mora said. "I don't know that, I can't guarantee that. I can't guarantee that we would have had unbelievable success."

"(San Francisco had) really good players, a lot of Hall of Famers. I mean their backup quarterback was Steve Young. They were just really talented, a great coach, a great coaching staff. They were just really good. We had some really good games with them, just didn't win enough."

Former Saints quarterback Bobby Hebert (1985-89, '91-92) said there's no doubt that the Saints would have achieved more success if not for San Francisco. Hebert-led Saints teams posted a 20-game winning streak against AFC opponents.

"In 1991 we won the NFC West, we were 11-5," Hebert said. "We were 12-4 (in '92), we were a wild card team. I mean, you think you win 12 games, you're going to win your division. No, we were a wild card team.

"It was because we were 12-4, the 49ers were 14-2, so it was just wrong place, wrong time. (But) it was a rivalry; the fans knew that we were going to compete."

The competition continues Sunday, in the Superdome. The rivalry isn't as intense as before, but the reward is just as significant.