On 17 March, the U.S. 1st Infantry Division moved forward into the almost abandoned plains, taking the town of Gafsa and starting to set it up as a forward supply base… the 1st Ranger Battalion—led by Colonel William O. Darby—pushed ahead, and occupied the oasis of El Guettar… Another operation by the Rangers took one of the Italian positions and 700 prisoners on the night of 20 March, after scaling a sheer cliff and passing ammunition and equipment up hand-over-hand. They were now in an excellent position for an offensive.
The Axis… decided that the 10th Panzer Division should stop them…. Von Arnim held Rommel′s opinion on the low quality of the U.S. forces and felt that a show of force would be enough to clear them from the Eastern Dorsals again. At 06:00 on 23 March, 50 tanks of Broich′s 10th Panzer emerged from the pass into the El Guettar valley…. They quickly overran front-line infantry and artillery positions. Major General Terry de la Mesa Allen, Sr.—commanding the U.S. 1st Infantry Division—was threatened when two tanks came near his headquarters, but he shrugged off suggestions of moving, "I will like hell pull out, and I'll shoot the first bastard who does."
German efforts took a turn for the worse when they ran into a minefield. When they slowed to clear the field, U.S. artillery and anti-tank guns opened up on them, including 31 potent M10 tank destroyers which had recently arrived. Over the next hour, 30 of the 10th Panzer′s tanks were destroyed, and by 09:00 they retreated from the valley.
A second attempt was made starting at 16:45, after waiting for the infantry to form up. Once again the U.S. artillery was able to disrupt the attack, eventually breaking the charge and inflicting heavy losses. Realizing that further attacks were hopeless, the rest of the 10th dug in on hills to the east or retreated back to German HQ at Gabès.