UFC 31: Locked and Loaded | Event Profile, Full Results & Legacy

Conor McBragger
6 days ago
4 min read

Introduction

UFC 31: Locked and Loaded. May 4, 2001. Mark G. Etess Arena, Atlantic City, New Jersey. The second event under Zuffa ownership, and the card that introduced the modern UFC weight class structure. Bantamweight was renamed Lightweight and raised from 150 to 155 pounds. Welterweight became fixed at 170, Middleweight at 185, Light Heavyweight at 205. The new UFC logo appeared on the Octagon canvas for the first time.

The card featured two title fights and a generation of debuts. B.J. Penn made his professional MMA debut, stopping Joey Gilbert in the first round. Matt Serra appeared for the first time, losing a spectacular fight to Shonie Carter via spinning backfist KO in the third round. Chuck Liddell knocked out Kevin Randleman in 1:18. Carlos Newton submitted Pat Miletich to win the Welterweight Championship. Randy Couture survived five rounds with Pedro Rizzo to retain the Heavyweight Championship in what many consider the first truly great five-round heavyweight title fight.

Quick Stats

📅 Date: May 4, 2001

📍 Venue: Mark G. Etess Arena, Trump Taj Mahal, Atlantic City, New Jersey, USA

🏆 Heavyweight Championship: Randy Couture (c) def. Pedro Rizzo — Decision (Unanimous) — R5, 25:00

🏆 Welterweight Championship: Carlos Newton def. Pat Miletich (c) — Submission (Bulldog Choke) — R3, 2:50 (New champion)

🌟 Debuts: B.J. Penn (pro MMA debut), Matt Serra, Semmy Schilt; Shonie Carter KO spinning backfist vs. Serra

📜 Historic: New UFC weight class structure finalised; new UFC logo on canvas; Liddell KOs Randleman in 1:18

Couture vs. Rizzo: A Classic Championship Fight

Randy Couture’s first title defence against Pedro Rizzo was the most competitive heavyweight title fight the UFC had produced. Rizzo nearly finished Couture in round two with a body kick that dropped him. Couture recovered and spent rounds three through five wrestling Rizzo and grinding out damage from top position. Both men were bloodied. The unanimous decision for Couture was close enough that Rizzo was convinced he had won.

The fight demonstrated that the Heavyweight Championship under Couture was going to be contested properly — sustained, technical, physically demanding. It was the most complete five-round performance the division had seen, and it set the tone for what Couture’s reign would look like.

B.J. Penn and the Spinning Backfist

B.J. Penn made his professional MMA debut at 22 years old, stopping Joey Gilbert by TKO with punches at 4:57 of the first round. Penn had won the ADCC Submission Wrestling World Championship earlier in 2000 as a no-name competitor. His UFC debut signalled a fighter of unusual ability was entering the sport.

The Matt Serra vs. Shonie Carter fight went three rounds before Carter landed a spinning backfist that knocked Serra cold at 4:51. Carter had been losing on the scorecards. The finish is one of the most replayed moments in early Zuffa-era UFC history.

Full Results

Preliminary Bouts

Tony DeSouza def. Steve Berger — Decision (Unanimous) — R3, 15:00

B.J. Penn def. Joey Gilbert — TKO (Punches) — R1, 4:57 (Penn pro MMA debut)

Main Card

Matt Lindland def. Ricardo Almeida — DQ (Grounded Kicks) — R3, 4:21

Semmy Schilt def. Pete Williams — TKO (Punches) — R2, 1:28 (Schilt debut)

Shonie Carter def. Matt Serra — KO (Spinning Backfist) — R3, 4:51 (Serra’s UFC debut ends in stunning KO loss)

Chuck Liddell def. Kevin Randleman — TKO (Punches) — R1, 1:18

UFC Welterweight Championship

Carlos Newton def. Pat Miletich (c) — Submission (Bulldog Choke) — R3, 2:50 (Newton becomes new UFC Welterweight Champion)

UFC Heavyweight Championship (5 rounds × 5 minutes)

Randy Couture (c) def. Pedro Rizzo — Decision (Unanimous) — R5, 25:00 (Couture’s first successful HW title defence)

Records & Milestones

🏆 Carlos Newton becomes UFC Welterweight Champion — the Canadian submission specialist ended Pat Miletich’s reign with a bulldog choke in the third round.

🌟 B.J. Penn pro MMA debut — the future multi-divisional UFC champion and ADCC champion made his first professional appearance, winning by TKO.

💥 Shonie Carter spinning backfist KO — one of the most replayed finishes in early Zuffa-era UFC history, against a debuting Matt Serra who was winning on the cards.

📝 Modern UFC weight classes introduced — Lightweight at 155, Welterweight at 170, Middleweight at 185, Light Heavyweight at 205; the framework still used today.

Legacy & Impact

UFC 31 is where several careers that would define the next decade of UFC history properly began. Penn’s debut, Serra’s debut, Liddell’s continued rise, Newton’s title win, and Couture’s first successful defence are all part of a card that reads, in retrospect, like a road map of where the sport was heading.

The Couture/Rizzo fight was a statement of intent for the Heavyweight division. Five rounds, both men nearly finished, decided by a close unanimous decision. It set the standard for what a heavyweight title fight could be in a sport that was finally starting to operate with consistent rules, consistent weight classes, and consistent regulation.

FAQ

What happened with the UFC weight classes at UFC 31?

At UFC 31, the modern UFC weight class structure was formally adopted: Lightweight at 155 lbs, Welterweight at 170, Middleweight at 185, Light Heavyweight at 205. This replaced the earlier SEG-era system and matched the Unified Rules framework adopted by the New Jersey State Athletic Control Board. These divisions remain the standard today.

Was UFC 31 B.J. Penn’s first fight?

Yes. UFC 31 was B.J. Penn’s first professional MMA fight. He defeated Joey Gilbert by TKO (punches) at 4:57 of the first round. Penn had won the ADCC Submission Wrestling World Championship in 2000 before making his MMA debut. He would go on to become a two-division UFC champion.

How did Shonie Carter KO Matt Serra at UFC 31?

Carter landed a spinning backfist at 4:51 of the third round that knocked Serra unconscious. Carter had been losing on the scorecards entering the final round. The finish is one of the most famous KOs in early UFC history and is frequently cited as an example of a fight changing completely in a single moment.