Denver and Toronto started this second round of the playoffs feeling great about their chances.

And then things went bad.

And then they bounced back.

So now, going into a pair of big-time swing games on Tuesday night — Denver plays host to Portland, Toronto plays host to Philadelphia — the Nuggets and Raptors can either take a firm grip on their respective series or get themselves into pits of trouble that would be even deeper than the ones they were in a couple of days ago.

Game 5s await. Blazers-Nuggets, tied 2-2. 76ers-Raptors, tied 2-2. Toronto and Denver both reclaimed home-court advantage with series-tying road wins on Sunday, and the task now is to keep that momentum going with very high stakes.

“You win a game, and you’ve got to play another one,” Raptors coach Nick Nurse said today. “To borrow a phrase that everybody uses, this is a grind. These things are grinders, and being even-keeled, professional, hard-working, tough mentality is what it needs on each game and each possession, really, on both ends.”

Sunday’s situation was dire for Denver and Toronto: A loss would have meant a 3-1 series deficit, which is almost always a precursor to elimination.

The trick now, Nuggets coach Michael Malone said Monday, is to keep that same level of desperation — a lesson his team learned in Round 1.

“Well, it is dire,” Malone said. “It’s a best-of-three … and we don’t want to do all that work to allow them to come in and win Game 5 and have a chance to close it out in Game 6 back in Portland. We attacked it the same way in Round 1 in the same scenario. We beat San Antonio down there in Game 4 and we approached Game 5 like it was all or nothing. And we were able to get that win. So, it’s the same thing for us now.”

Kawhi Leonard’s numbers have been ridiculous for Toronto so far in this Eastern Conference semifinal series: He’s averaged 38 points, nine rebounds and four assists on 62 percent shooting.

He’s scored 152 points in the series. Philadelphia’s top two scorers, Jimmy Butler and Joel Embiid, have 163 combined in the four games.

“He’s been really, really, good,” Nurse said of Leonard. “From my vantage point, it’s been really fun to watch. And we’ve needed him to be that good.”

Meanwhile, Denver has gotten help from a perhaps surprising source. Will Barton suddenly isn’t an offensive liability anymore.

Booed at home while going 1 for 10 from the floor against San Antonio last month and benched for Torrey Craig not long afterward, Barton finally found his shooting touch in Portland. All 22 of his points in the Nuggets’ 140-137 quadruple-overtime Game 3 loss came after the third quarter. And Barton had two crucial 3-pointers in the fourth quarter of Denver’s 116-112 win in Game 4.

“I thought those two 3s in that fourth quarter were huge for us,” Malone said. “It’s back and forth, neither team could really get a stop in the fourth quarter. But we kept on answering the bell. We scored enough points and Will’s 3s were a big part of surviving their push at the end of that quarter.

“And hopefully that continues into Game 5.”

A look at Tuesday’s games:

76ERS AT RAPTORS

Series tied 2-2. Game 5, 6 p.m., TNT

>> Need to know: Not that this technically matters to either team, but history shows how vital Game 5 wins are in a series that is tied at 2-2. Each of the last five times that Toronto has been in a series tied 2-2, the Game 5 winner has ultimately advanced. And in Philadelphia’s case, this is the 25th time in franchise history that it has been in a 2-2 matchup. The Game 5 winner has won 24 of those series.

>> Injury watch: More of a health watch in this case, but Embiid was impeded by illness big-time in Game 4. When he was on the floor, the 76ers controlled play at both ends. When he wasn’t, the 76ers simply could not score — and Toronto took advantage of his absences to win the game.

>> Keep an eye on: Kyle Lowry and Danny Green. Everything is running through Leonard right now, and rightly so, but Toronto has to be thinking that either — or both — of these guys are overdue for a big game.

>> Pressure is on: Ben Simmons. The Philadelphia guard has 40 points, 37 shot attempts and 19 assists in 153 minutes. Too quiet.

TRAIL BLAZERS AT NUGGETS

Series tied 2-2. Game 5, 4:30 p.m., TNT

>> Need to know: Could this series be more even? No, probably not. Total points, Denver leads 464-462. Field goals, Denver leads 169-168. Both teams have exactly 44 3-pointers. Both teams have exactly 82 free throws made.

>> Injury watch: Portland center Enes Kanter battled through 29 minutes of Game 4 with his ongoing shoulder problem.

>> Keep an eye on: Portland’s starters. Blazers reserves like Seth Curry, Rodney Hood and Zach Collins were great in Game 4, but the starting five couldn’t generate any real sustained success.

>> Pressure is on: Denver. Yes, the Nuggets went through a seven-game grind in Round 1. But the Blazers won’t rattle easily and know they can win on the road.