Colsaerts had a putt for par at the first, which would have halved the hole as Johnson knocked his approach stone dead.
He was unable to find the bottom of the cup and America took a one-up lead.
A double bogey from Johnson allowed the Belgian to level the match at the fourth.
Johnson gave himself a fantastic opportunity for an eagle at the par-five fifth hole, but could not drop it and Colsaerts remained all square.
The American reclaimed the lead with a birdie at the par-four fourth hole, but Colsaerts stiffed his approach to the ninth to put pressure on Johnson, whose shot was wayward.
Colsaerts once again squared the match with his birdie. Colsaerts could have gone ahead for the first time in the match with a putt from four feet at the 10th.
However, he ended up three putting to concede the hole to Johnson, who stretched his lead to two holes at the next.
Johnson began to stutter, and two successive pars were enough for Colsaerts to haul him back to parity for the third time in the match.
Just when the Belgian looked to have the impetus, it quickly shifted Johnson's way.
Birdies at 14 and 15 and a par at 16 saw him take the match and win the USA's first point of the singles matches.