Howard hit a go-ahead two-run single in the ninth inning and the Phillies rallied past the Toronto Blue Jays 7-6 on Friday.
"This is what we're capable of doing," Howard said. "But at the same time, you've got to know that baseball is an up-and-down type game. As long as you can outscore your opponent, that's the name of the game. It doesn't matter how many runs you get."
The Phillies, owners of the best record in baseball, have succeeded mostly thanks to strong pitching and scoring more than their staff allows. They entered play Friday ranked eighth in the NL in runs and 13th in the majors.
"I'm tired of hearing everybody talk about how many runs we don't score," Howard said after Thursday's 5-2 loss to the Boston Red Sox. "We score enough runs to win games and that's what's important."
They scored just enough Friday, rallying from a 6-5 deficit in the ninth against Blue Jays closer Frank Francisco.
"The ball was really tailing away from him," Phillies manager Charlie Manuel said. "That wasn't an easy play."
Blue Jays manager John Farrell said he considered putting a defensive replacement in for Rivera but decided against it.
"Anytime you give up those type of plays and give an extra out, those are hard to overcome," Farrell said.
Howard followed with a two-run single to center, giving Francisco (1-4) his fourth blown save in 13 chances.
"Both teams battled hard, neither team wanted to budge," Howard said. "It was pretty much a fight all the way down to the end."
Philadelphia's late comeback overcame Jose Bautista's 25th home run and a mammoth two-run drive by Toronto rookie outfielder Eric Thames. The Blue Jays have homered in a season-high nine consecutive games, hitting 15 in that span.
Starting in place of injured right-hander Roy Oswalt (back), Phillies right-hander Kyle Kendrick allowed six runs and eight hits in seven innings, matching his longest start of the season. He walked one and struck out five.
"He kept us in the game," Manuel said. "He pitched a Kyle Kendrick game. That's how I looked at it. He battled and stayed in there."
The Blue Jays jumped on Kendrick with two in the first. Shortstop Yunel Escobar had to leave the game for X-rays after being hit on the left hand by a pitch, with Aaron Hill replacing him. One out later, Hill went to third on Bautista's ground-rule double, with both runners scoring on Edwin Encarnacion's double.
X-rays and a CT scan came back negative and Escobar is day to day.
Ben Francisco hit an RBI double in the second and the Phillies tied it with an unearned run in the third. Utley was hit by a pitch and went to second when Howard reached on Hill's fielding error. Victorino followed with an RBI single.
Thames put Toronto back on top in the fifth with a massive two-run homer into the third deck in right, his second.
The Phillies took a short-lived lead in the top of the seventh. Howard chased Blue Jays left-hander Ricky Romero with a sharp single through the shift and scored when Victorino tripled off Jason Frasor. Ben Francisco followed with a sacrifice fly to left, with Victorino sliding home safely ahead of a wide throw from Rivera.
Romero allowed four runs, three earned, and seven hits in 6 1/3 innings, the first time in 10 starts he's failed to work at least seven frames. Romero walked four and struck out three.
Toronto reclaimed the lead in the bottom half when Bautista hit a two-run homer to left, his 25th, tying New York Yankees slugger Mark Teixeira for the major league lead. Bautista went 2-for-3 with a double and a walk and scored twice.
Before the game, former Blue Jays pitcher Roy Halladay received a standing ovation as he carried the lineup card to home plate. Halladay tipped his cap to the Canada Day crowd of 45,512 and shook hands with Blue Jays third base coach Brian Butterfield.
"I thought it was great, very classy," Howard said. "For what he's done here for the city and the organization, I thought it was very nice for them to recognize that."
Halladay, who won 148 games in 12 seasons with the Blue Jays, was traded to Philadelphia following the 2009 season. This is his first appearance in Toronto since the trade. He'll face the Blue Jays on Saturday, pitching against right-hander Carlos Villanueva.
The Blue Jays were scheduled to host the Phillies in June 2010, but the series was moved to Philadelphia because it conflicted with the G20 Summit in downtown Toronto.
Phillies left-hander Cole Hamels, who left Thursday's start against Boston after four innings after being hit in the glove hand by a batted ball, played catch before the game and will throw a bullpen session Saturday. ... Phillies shortstop Jimmy Rollins, who is nursing a sore right shoulder, started at DH, with Wilson Valdez playing short. ... Philadelphia infielder Brian Bocock has been outrighted to Triple-A Lehigh Valley and taken off the 40-man roster. ... Canadian Hall of Famer Ferguson Jenkins attended the game. ... The crowd was Toronto's biggest since drawing 47,984 on Opening Day.