I am looking for a phrase or a flowery way to say that he made hard work of what should have been a cakewalk. To give more context - sometimes the commentator says that the team should have finished the game easily but they made it look tough. Any suggestions?
How about to "make a mountain out of a molehill (tfd)". The link to the free dictionary says "cliché: to make a major issue out of a minor one; to exaggerate the importance of something"
You could describe the person as having "snatched defeat from the jaws of victory", a reversal of "snatch victory from the jaws of defeat".
According to Wiktionary, the latter phrase came into being as follows:
The first recorded use of the phrase discovered to date is an article criticizing Representative James Seddon of Virginia for claiming that a regiment in the Mexican-American war had "snatched victory from the jaws of defeat."
There is also the well-known idiom, "to make a mountain out of molehill" — though this also has an additional meaning, 'to make a big fuss over a trifling matter'.
I have heard the phrase "He made a meal out of that..." used to indicate something was made harder than it should otherwise be.
See Cambridge dictionary: http://dictionary.cambridge.org/dictionary/british/make-a-meal-out-of-sth
How about making your own phrase like "engineered a rube goldberg"
From wikipedia "A Rube Goldberg machine is a contraption, invention, device or apparatus that is deliberately over-engineered or overdone to perform a very simple task in a very complicated fashion, usually including a chain reaction. The expression is named after American cartoonist and inventor Rube Goldberg (1883–1970).
Over the years, the expression has expanded to mean any confusing or complicated system. For example, news headlines include "Is Rep. Bill Thomas the Rube Goldberg of Legislative Reform?" and "Retirement 'insurance' as a Rube Goldberg machine".