UFC 53: Heavy Hitters was a mixed martial arts event held by the Ultimate Fighting Championship on June 4, 2005, at the Boardwalk Hall in Atlantic City, New Jersey. The event was broadcasted live on pay-per-view in the United States, and later released on DVD. Headlining the card were Andrei Arlovski, the Interim Heavyweight champion, and Justin Eilers.

Although there was some criticism directed at the UFC for giving Eilers a title shot after coming off a knockout loss to Paul Buentello at UFC 51, the UFC explained that Buentello was not medically cleared to fight when the main event was originally scheduled.

Preliminary Card

Welterweight Bout
Nick Diaz vs. Koji Oishi
Diaz defeats Oishi by knockout (punches) at 1:24 of round one. Oishi was a representative of Pancrase. The bout, although preliminary, was aired on the broadcast.

Middleweight Bout
David Loiseau vs. Charles McCarthy
Loiseau defeats McCarthy by technical knockout (strikes) at 2:10 of round two. The bout, although preliminary, was aired on the broadcast.

Middleweight Bout
Nathan Quarry vs. Shonie Carter
Quarry defeats Carter by technical knockout (strikes) at 2:37 of round one. The bout, although preliminary, was aired on the broadcast.

Main Card

Heavyweight Bout
Paul Buentello vs. Kevin Jordan
Buentello defeats Jordan by submission (guillotine choke) at 4:00 of round one.

Light Heavyweight Bout
Forrest Griffin vs. Bill Mahood
Forrest Griffin, the Light Heavyweight winner of The Ultimate Fighter, defeats Bill Mahood by submission (rear naked choke) at 2:18 of round one.

UFC Middleweight Championship
Evan Tanner (C) vs. Rich Franklin
Rich Franklin defeats defending champion, Evan Tanner, by technical knockout (doctor stoppage) at 3:25 of round four. Halfway through the fourth round, the referee stopped the action to check the cuts on Tanner's face; at this point, the ringside doctors called an end to the bout. Franklin becomes the UFC Middleweight champion.

Welterweight Bout
Karo Parisyan vs. Matt Serra
In the evening's swing bout,Parisyan defeats Serra by unanimous decision.

UFC Heavyweight Championship
Andrei Arlovski (Interim Champion) vs. Justin Eilers
In the main event of the evening, Interim Heavyweight champion, Andrei Arlovski, successfully defends his title and defeats Justin Eilers by technical knockout (strikes) at 4:10 of round one. It was soon realized that Eilers had injured his knee in the bout, prompting the referee to stop the fight as Eilers could not defend himself.