Wheat, having reminded investors on Monday that the last shall be first, called to mind another adage on Tuesday – what goes up must come down.
The grain's effort to hold on to Monday's gains faltered in live trading in Chicago as funds gave in to the temptation to book profits.
"Wheat continues to work lower under local and fund selling, some of which is long liquidation," Vic Lespinasse, GrainAnalyst.com analyst, said.
"This is a disappointing performance as far as the bulls are concerned."
US data showing the winter wheat harvest ticking along and spring wheat still in good health did little to discourage selling.
The September contract stood 11.25 cents, or 2.1%, lower at $5.31 ½ a bushel at 16:30 GMT, with 2010 lots showing similar losses.
European wheats, which failed to share much of Chicago's gains on Monday, were spared a fall-out on Tuesday too.
Paris's August contract was unchanged at E137.25 a tonne, with London wheat for November delivery losing £1.00 to £112.00 a tonne.
Paris rapeseed, however, did better, up E3.25 at E280.25 a tonne.
Indeed, it was a better day for oilseeds. In Kuala Lumpur, palm oil bounced 2.3% from a three-month low to close at 2,036 ringgit a tonne, helped by hopes for stronger Malaysian exports.
Chicago soybeans for September were 7 cents higher at $10.25 ½ a bushel.
Oil markets helped a touch, with Brent crude for August adding $0.02 to $60.71 a barrel amid some thawing of fears for the global economy.
Shares, in fact, were also a little firmer in the US and Europe following a second successive rise in monthly American consumer confidence data.
Still, corn was the pick of the crop in Chicago, adding 5 cents to $3.36 ¾ a bushel for September delivery.
Some traders cited concerns over drier weather in corn-growing areas, which could hurt yields, with others saying the crop may have been oversold since the US two weeks ago estimated this year's plantings at the highest since 1946.
Among soft commodities, the day belonged to juice, which remained in strong demand.
The nearest contract, September, added 2.5% to 97.50 cents a pound, after touching a 10-month high of 97.70 cents a pound earlier.
The second-nearest contract, November, crossed the $1 mark, adding 2.2% to 100.60 cents a pound.
Juice's strength has somewhat puzzled traders, coming in the absence of any significant negative crop news, such as a hurricane, which could send the Florida harvest for six.
"It seems to be speculative buying on technical [factors]," one trader told Reuters, the news agency.
Juice's performance overshadowed a strong day for cocoa too, with London's September contract closing up 1.5% at £1,750 a tonne, and its New York equivalent adding 2.4% to $2,727 a tonne.
The rises followed reports of heavy rain in the Ivory Coast, the world's main producer of cocoa beans, with forecasts of an El Nino weather pattern further concerning investors.