UFC

Conor McGregor says Nate Diaz will NOT make it to the 3rd round of their rematch ... predicting a 2ND ROUND K.O. at UFC 202.

McGregor was answering questions on the UFC 202 media conference call Friday -- when he admitted that he underestimated Nate's chin and toughness the first time around ... but he won't make that mistake again.

"He weathered the storm," Conor said ... "I'm just gonna be a lot more prepared for a man that can stay in there with me."

That being said ... Conor said confidently -- "I will K.O. him inside the 2nd round."

Luke Rockhold says the UFC needs to do something drastic to end the cheating -- telling TMZ Sports, "I'm just tired of talking about it over and over again and nothing happens."

Rockhold says people have short memories when it comes to cheating in MMA -- and said Anderson Silva is the perfect example.

"Everyone is gonna beat down Jon Jones ... and they're gonna cheer Anderson Silva after coming back from testing positive."

FYI, Silva received a 1 year suspension last year after testing positive for a PED at UFC 183.

So, what's the solution?

"They need to implement the full 2 year ban at least. 4 years would really scare a person because it would take away a career."

UFC champ Tyron Woodley watched the TMZ Sports video of Nick Diaz going off about a possible fight for the belt -- and says one thing is clear to him ... Nick's an idiot.

Woodley joined the guys on the "TMZ Sports" TV show (airs Monday night on FS1) and clapped back at Diaz ... saying he was trying to COMPLIMENT the guy as a great fighter to set up a big money fight.

But Woodley says Diaz took the message the wrong way -- "He made no sense."

"It just shows you his I.Q. outside of fighting is not extremely high."

Woodley says Diaz may have blown his shot at the title -- and hinted that he's closer to locking up a fight with Georges St-Pierre.

There's A LOT more in the full interview tonight on FS1.

Nick Diaz is FIRED UP -- telling TMZ Sports he's still the BEST FIGHTER in his weight class ... and he's down to fight Tyron Woodley ... or ANYONE the UFC throws at him, if the price is right.

Woodley called Diaz out after he beat Robbie Lawler at UFC 201 this weekend -- and now that Diaz finished his suspension and can fight again ... Nick says he's ready to take on the world.

"I want to fight the best guy. I always want to fight the best guy. The thing is I'm on top ... I'm the one on top ... they're dropping MY name."

"I don’t need no fake ass piece of plastic. F*** that! I made PPV without a title. I don't need that fake ass plastic to be somebody."

For what it's worth, we're told the UFC is gunning to get Diaz a fight quickly -- but we're told the name being thrown around is Robbie Lawler.

He breaks up fights in the Octagon, but UFC ref Herb Dean says there's no way in hell he's breaking up fights in the street!

Dean -- considered by many to be the best ref in MMA -- was at LAX when we asked if he's ever seen a real-life brawl and felt compelled to get involved.

The short answer -- HELL NO.

"If I see a fight in real life, I'm running in the other direction," Dean said.

"I've walked by street fights ... and somebody watching will recognize me and say, 'Hey Herb' ... I'm like, 'I'm a professional, this is amateur!'"

UFC fighter Alan Jouban thinks the time is now for Ronda Rousey to return to the Octagon ... saying she dominated the sport like no other female fighter ... and he can't wait for her return.

We got Jouban out in L.A. and asked him what's up with the one-and-done championship runs in the women's bantamweight division since Ronda lost to Holly Holm?

Jouban told our guy the short reigns have less to do with the new fighters ... and more to do with the old one ... saying Rousey was so DOMINANT it made the division look weaker than it really was.

Guy's got a point ... the title has changed hands like three times since Ronda was holding it down ... and now that we know she doesn't have a baby on board ... we're wondering when she'll get another crack at it.

The UFC is cracking down on PED usage in a way boxing DESPERATELY needs ... that's according to former boxing World Champ Paulie Malignaggi ... who says it's HIS sport that needs a scrubbing.

We got Paulie -- the former junior welterweight and welterweight champ of the world -- in NY training for his big Showtime PPV fight against Gabriel Bracero on Saturday and asked him about recent drug scandals in combat sports.

A fair share of those have gone down in the UFC ... where high-profile guys, like Brock Lesnar and Jon Jones, have been popped just recently for doping.

Paulie's been a vocal critic of PED use in boxing for a long time ... but given recent history it's still interesting to hear him say that it's HIS sport ... and not the UFC ... that has the real problem.

UFC superstar Nate Diaz just FaceTimed into the "TMZ Sports" TV show -- and told us he's on the way to his hometown Stockton, CA ... to get ready for the McGregor fight with "the best training in the world."

Diaz says he's been working out in L.A. -- but now, he's kicking the training into high gear -- "I'm going home now where I got all my good s*** at."

Straight from the champ's mouth ... Amanda Nunes says she wants to get in the Octagon with Ronda Rousey as soon as possible -- if Ronda actually fights again.

Nunes -- who just beat Miesha Tate to win the Women's bantamweight title -- was doing a media event for UFC 201 and was asked who she would pick for her first title defense.

Nunes didn't hesitate -- "Ronda Rousey" ... but only IF the UFC legend decides to fight again.

Nunes says it's important for her to square off with Ronda "to prove to everybody one more time I deserve to be here."

It's a good problem to have ... but Dana White says family members are coming out of the woodwork with their hands out after the UFC sold for $4 BILLION ... so he's ignoring their calls!

White was on 'Kimmel' Thursday night -- and was asked how his life has changed now that he's insanely rich (Jimmy estimates he made $360 mil off the deal).

We're guessing Dana was joking about the family -- but says he had a real Howard Hughes moment and locked himself in a hotel room after the deal closed.

Ronda Rousey is NOT with child ... despite rumors perpetuated by rival UFC fighter Cris "Cyborg" Justino, so says UFC prez Dana White.

Early Thursday, Cyborg went to Twitter and wrote, "I keep hearing the rumor @RondaRousey is expecting and no longer fighting #ufc205 if true congrats on the new life."

Ronda has previously talked about having children with her boyfriend, Travis Browne -- but never gave a time frame.

We spoke with White ... who tells us he talked with Ronda on the phone after the Cyborg tweet and she assured him it just ain't true.

Still no word on when she's expected to get back in the Octagon.

Boxing legend Ricky Hatton says he has a lot in common with Conor McGregor -- and he's even got some advice for the UFC superstar.

Hatton was a damn good boxer back in the day -- racking up a 43-0 record before finally losing to Floyd Mayweather in 2007.

We asked how he felt about comparisons between him and Conor over the years -- and Hatton seems pretty flattered by it ... explaining why he thinks they're two of a kind.

BTW, Ricky has now transitioned into trainer -- and is getting Sergey Rabchenko ready for his big Showtime fight Saturday night at Barclays Center.

Meantime, check out Hatton's greatest hits -- dude was beast.

Nate Diaz just gave the blow-by-blow on how Justin Bieber put an END to their famous celebrity beef back in March -- and the whole thing is pretty hilarious.

Of course, the two had gone back and forth on social media after the McGregor fight -- with Nate ultimately coming on the "TMZ Sports" show and saying, "F*** that fool."

As fate would have it, they came face-to-face in a Hollywood nightclub a few days later -- but Bieber's no dummy ... he immediately tried to bury the hatchet before things popped off.

You gotta hear Nate tell the story on "Conan" Tuesday night ... not only did they bro-hug it out, but they're boys now!

UFC badass Valentina Shevchenko -- who beat up Holly Holm this weekend -- tells TMZ Sports she wants the belt ... BADLY ... and she's ready to go through Amanda Nunes or Ronda Rousey to get it.

FYI, Shevchenko lost to Nunes by unanimous decision back in March -- but Valentina says she's at the top of her game now ... and is champing at the bit to get the current UFC women's bantamweight champion back in the Octagon.

"I know it will be a very difficult fight for her," Shevchenko said ... "I want it. I want it very much."

She also pitches her case to UFC honcho Dana White about why she should get the rematch.

Two titans of sport ... not one single chest hair.

Cristiano Ronaldo and Conor McGregor came face-to-face in Vegas this weekend ... and immediately took their shirts off.

He's already a UFC Hall of Famer ... but B.J. Penn could have been EVEN BETTER ... so says Dana White, who tells us the guy had the talent be one of the greatest MMA fighters of all time.

We spotted White in NYC -- and asked if there was a fighter who had insane raw talent ... but didn't have the drive to reach their full potential.

"B.J. Penn," White said ... "B.J. Penn probably should have been one of the best ever ... to ever live ... to ever do it. B.J. was so talented."

"I think B.J. in his own words would go back and do things differently if he could."

B.J. was 28-10-2 in his MMA career -- but couldn't figure out a way to beat guys like Frankie Edgar (lost 3 times) and Georges St-Pierre (lost twice).