Gabriel and Shillingford snared nine second-innings wickets between them as the Windies stormed to a nine-wicket win in Bridgetown last week.
And the duo claimed all three victims to fall before lunch on Wednesday.
After being sent into bat, Zimbabwe made a flying start with Vusi Sibanda shining in a first-wicket partnership with Tino Mawoyo that brought 42 runs in the opening eight overs.
However, the introduction of Gabriel in the ninth over changed all that as he struck with his sixth delivery, Mawoyo shouldering arms to a ball that went straight on to be bowled for eight.
The 24-year-old paceman then dismissed the quick-scoring Sibanda for 32 in his next over. The opener was looking to club a full toss away for his seventh boundary but only succeeded in picking out Kemar Roach at mid-on.
That left Zimbabwe on 43 for two and the tourists could only add 21 more runs before losing their third batsman, spinner Shillingford bowling Hamilton Masakadza for 14.
Zimbabwe, who were skittled for 107 in their second innings in Bridgetown, must have been fearing another collapse at that point but captain Brendan Taylor (25 not out) and Craig Ervine (five not out) ensured there were no more setbacks before lunch.