"Look at these, bro," he recalled telling Nava, pointing down to a shoe a friend brought him for the game. It had the Rally Monkey -- a staple of the club's home games -- airbrushed on the side.
Expect Santiago to keep wearing the new spikes.
Albert Pujols hit his 575th career homer -- a two-run shot -- and had five RBIs for the Angels, who had lost 10 of their past 11 games.
"There's no doubt a game like this is fun," Angels manager Mike Scioscia said. "It comes at a good time just too hopefully get a little momentum going and hopefully we'll carry it over to tomorrow."
Cron and Perez each homered during the 11-run seventh. They are the first set of teammates with at least five hits and five RBIs in the same game since Gene Moore and Buck Jordan for the Boston Braves in 1936, according to ESPN.
"We were sitting down: me, Nava and [Jhoulys] Chacin,'' Santiago said. "We were saying 'We're not moving.' That was awesome, man. We needed that. That was awesome to watch."
It's the sixth time the Angels reached 20 runs, the last coming against Kansas City on Aug. 25, 2004. The club record for runs is 24, set at Toronto on Aug. 25, 1979.
The 21 runs matched Los Angeles' combined output from its past six games, and the Angels' 22 hits were the most for the franchise since a 17-8 win over Baltimore on Aug. 16, 2009.
"I think if you play baseball long enough you have games like this," Boston second baseman Dustin Pedroia said. "You have to turn the page and try and win the series tomorrow."
Mookie Betts had a solo homer and three hits for Boston, which won the series opener after losing four of five.
Red Sox outfielder Ryan LaMarre pitched the ninth, giving up no runs and two hits.
"Honestly, we're embarrassed by tonight's ballgame," Red Sox manager John Farrell said. "There's really no other way to put it. We got kicked around the ballpark tonight."
Santiago (5-4) got the win, holding the majors' highest scoring team to one unearned run and four hits over six innings.
Clay Buchholz gave up six runs -- three earned -- in 4⅓ innings.
With Los Angles leading 4-0 in the fifth, Perez's three-run double capped a five-run inning that broke it open. Buchholz (3-9) was lifted with runners on first and second with one out. Travis Shaw then fired high to second for an error on a probable double-play grounder by Pujols, with the relay late to first. One out later, Cron hit his two-run single.
Johnny Giavotella singled to re-load the bases before Perez cleared them with a double off the center-field wall.
Cron homered over the Monster in the fourth to make it 4-0.
Pujols is eight behind Mark McGwire for 10th on the career homer list.
During the 11-run seventh, Pujols had a three-run double, Cron a two-run homer and Perez added a two-run shot, which brought mock cheers from the Fenway Park fans. The inning put Los Angeles ahead 20-1.
Angels: 3B Yunel Escobar returned to the lineup after missing seven straight with a tender left knee. He batted leadoff and went 1-for-4 before being lifted for a pinch runner.
Red Sox: Farrell said switch-hitting OF/C Blake Swihart (sprained left ankle) took BP indoors, but only from the left side to avoid stress on the ankle. ... The manager also said that RHP Joe Kelly (demoted to the minors last month) threw a 40-pitch session Saturday as he works to come back from a groin injury. When healthy, the plan is to shift him to relief and prepare him to work out of Boston's bullpen.
Angels: RHP Matt Shoemaker (3-8, 4.12 ERA) looks for better luck this month starting in the series finale on Sunday. He was winless in six June starts, going 0-3 despite a 2.14 ERA.
Red Sox: RHP Sean O'Sullivan (1-0, 7.94) is slated to start for Boston.
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