There have been frequent clashes along the Gaza border since the Palestinians began organising regular mass protests there in March 2018 but Saturday's exchange was unusual because of the weaponry the army claimed was involved in the Palestinian side.
"The terrorists were equipped with AK-47 assault rifles, RPG grenade launchers and hand grenades," an army statement said.
A spokesperson said: "The army opened fire after one of the terrorists scaled the barrier and hurled a grenade at the soldiers."
No casualties were reported in Israeli ranks.
Palestinian demonstrations at the Gaza border demanding the lifting of Israel's more than decade-old blockade has often led to violence and deadly response from the Israeli army.
At least 301 Palestinians have been killed by Israeli fire in Gaza or the border area since March 2018, the majority during the demonstrations.
Palestinians say US 'deal of the century' will finish off their state
Seven Israelis have also been killed.
The protests have declined in intensity in recent months following a truce brokered by UN officials and Egypt.
Under the truce, Israel agreed to take steps to ease aspects of its blockade in return for calm on the border.
Sporadic violence has continued but the Israeli army has said most of it has consisted of lone-wolf attacks.
On August 1, a Palestinian seeking to avenge his brother's death by Israeli fire entered Israel from Gaza armed with a Kalashnikov assault rifle and hand grenades. He was killed and three Israeli soldiers wounded, the army said.
Prime Minister Benjamin Netanyahu is widely seen as wanting to avoid a major flare-up in the Palestinian territories as Israel prepares for a snap general election on September 17, its second this year.
But he is likely to face political pressure to act firmly against any significant attack.
Israel and Hamas have fought three wars since 2008.
The border exchange came as Palestinians prepare to mark Eidul Azha, the feast of the sacrifice.
COMMENTS
Comments are moderated and generally will be posted if they are on-topic and not abusive.
For more information, please see our Comments FAQ