It took the Republican Party a few hours after votes closed to reach the required 50-seats majority, according to presstv.ir.
Trump was quick to brag about the victory.
The Republicans, who headed to the elections with a narrow 51-47 majority are now projected to open an even bigger gap.
So far they have won two of the 26 Democratic seats that were up for grabs.
In the State of Indiana, one of Trump’s three stops on the Election Eve, Republican challenger Mike Brawn defeated incumbent Democratic Senator John Donnelly by a healthy margin of almost 10 points (52.8 percent to 43.2 percent).
Republicans won big in North Dakota, as Kevin Cramer managed to knock seating Senator Heidi Heitkamp out of the Senate by a huge margin (56.5 percent to 43.5 percent).
But perhaps the most intense race took place in the state of Texas, where incumbent Senator Ted Cruz was projected by Fox News and other outlets to pull off a surprisingly close victory against his rival Beto O’Rourke in the traditionally Republican territory.
While Democrats were never projected as the favorites to flip the Senate, it is still surprising to see how they failed to make a splash despite receiving intense support from party heavyweights such as former President Barack Obama, former VP Joe Biden, and former First Lady Hillary Clinton.