"Don't get beat with the fastball, and hit the ball hard," he said.
One could say Wong accomplished both objectives.
Cracking the second grand slam of his career, Wong supplied all of St. Louis' offense in a 4-1 win Monday night at Busch Stadium.
It was the latest in a growing list of clutch homers for the second-year major-leaguer. In last year's postseason, he belted a seventh-inning tiebreaker in Game 3 of the National League Division Series against the Los Angeles Dodgers and a game-ender against the San Francisco Giants in Game 2 of the NL Championship Series.
Wong also owns two regular-season walk-offs against the Pittsburgh Pirates, the second coming May 3 to settle a 14-inning tussle.
"He doesn't shy away from any situation," Cardinals manager Mike Matheny said. "When you have some success in those big spots, you get more confident."
Nursing a 1-0 lead to that point, Iglesias was one pitch away from escaping his most serious jam. After allowing a leadoff double to catcher Yadier Molina and a single to left fielder Stephen Piscotty, Iglesias got a popup from first baseman Dan Johnson, hit center fielder Peter Bourjos with a pitch and whiffed pitcher Lance Lynn.
Iglesias fell behind Wong 2-0 and couldn't tempt him with high fastballs, as he did while striking him out an inning earlier.
"He made the adjustment," Iglesias said, speaking through an interpreter. "Being behind in the count, I had to come in with a fastball (over) the middle, and you saw the consequences."
Iglesias (1-3) gave up six hits and four runs over six innings with no walks and seven strikeouts. He and Lynn combined for five hit batters, and plate umpire Marty Foster doled out warnings after Bourjos was plunked with a slider in the sixth.
While St. Louis (64-35) made the most of its opportunity with the sacks packed, Cincinnati (43-54) didn't do enough damage to Lynn when it loaded the bases with no outs in the third.
Right fielder Jay Bruce produced the Reds' run with a sacrifice fly, but catcher Brayan Pena rapped into an inning-ending, 6-4-3 double play, enabling Lynn to escape a potentially big inning down just 1-0.
"Where they were in the lineup, to give up just the one run was huge," Matheny said. "Lance didn't have his best stuff tonight, but he was battling."
Lynn (8-5) gave up five hits and a run over seven innings with three walks and five strikeouts, upping his career record against Cincinnati to 7-3. His 115th pitch of the night induced a foulout from third baseman Todd Frazier with two men on to end the seventh, causing a frustrated Frazier to slam his bat.
Relievers Kevin Siegrist and Trevor Rosenthal mowed through the last two innings in 1-2-3 fashion, with Rosenthal bagging his 31st save.
The Cardinals upped their home record to 37-13 and hiked their National League Central lead over idle Pittsburgh to 6 1/2 games.
St. Louis catcher Yadier Molina left the game for a pinch hitter in the bottom of the fifth inning because he wasn't feeling well. Molina, who was hit in the mask by a foul ball in the first inning, passed concussion tests.
NOTES: St. Louis CF Randal Grichuk (groin) and 1B Mark Reynolds (hand) didn't play Monday, though they were available to pinch-hit. Grichuk was injured Sunday in the Cardinals' 3-2 loss to Atlanta, while Reynolds was drilled by a pitch Saturday night. ... Cincinnati recalled C Kyle Skipworth from Double-A Pensacola to take the roster spot of RHP Johnny Cueto, who was traded to Kansas City on Sunday. Skipworth was batting .237 with nine homers and 19 RBIs with the Blue Wahoos. ... The Cardinals activated RHP Mitch Harris (right groin) from the 15-day disabled list and optioned him to Triple-A Memphis.