BOXING: Gennady Golovkin floors Willie Monroe in sixth round to record 20th consecutive knockout victory and continue pursuit of showdowns with Miguel Cotto and Saul Alvarez

Gennady Golovkin's latest 'big drama show' had a few extra twists and turns. The middleweight champion still finished it with his usual show-stopping flourish.

Golovkin stopped Willie Monroe Jnr 45 seconds into the sixth round on Saturday night, retaining the 160-pound belts with his 20th consecutive knockout victory.

Golovkin (33-0, 30 KOs) put on another masterful performance in his adopted home of Los Angeles, knocking down Monroe twice in the second round and again in the sixth round of his 14th consecutive title defense.

Referee Jack Reiss raises the hand on Gennady Golovkin after his knockout of Willie Monroe Jr in Los Angeles on Saturday night

Former Kazakh Olympian Golovkin shows off his title belts after this Middleweight World Championship win over Monroe 

Golovkin celebrates with his growing Californian fanbase after his comprehensive win and 20th consecutive knockout success

The dominant Golovkin sends Monroe tumbling to the canvas in the sixth round. 'I'm done,' Monroe told referee Reiss shortly afterwards

Referee Jack Reiss delivers the count to a dazed Monroe after his knockdown in the sixth as Golovkin watches on from his corner

Monroe also hit the deck in the second round following a ferocious onslaught by Golovkin, who extended his professional record to 33-0 

The former Kazakh Olympian has stopped each of his 20 opponents since June 2008, and even a surprisingly strong fourth round from Monroe couldn't throw Golovkin off his path to the top.

'It was a good big drama show,' Golovkin said. 'I was happy with my performance. Willie is a very tough fighter. I felt very strong tonight. I knocked him down twice, but I didn't want an easy round the next round. I wanted to keep working.'

When Golovkin floored Monroe (19-2) with a long series of heavy punches in the sixth, the challenger declined to continue after his final trip to the canvas. 'I'm done,' Monroe told referee Jack Reiss.

Nicaragua's Roman 'Chocolatito' Gonzalez also defended his WBC flyweight title in style at the historic Forum with a furious second-round stoppage of Mexican veteran Edgar Sosa.

But Golovkin delighted a Southern California crowd of 12,372 backing the Kazakh champion who has gone from anonymity to stardom in less than three years. 

Golovkin counters with the left after Monroe's punch misses its target. The Kazakh fighter was dominant through the contest in California 

Monroe tries in vain to keep his balance after being floored by a ferocious Golovkin punch in the second round

Golovkin called out Miguel Cotto and Saul Alvarez following his latest victory. He intends to fight twice more before the end of the year

Monroe is forced back onto the ropes as Golovkin unloads another fierce right. His power was too much for Monroe, whose record is now 19-2

Golovkin realised a southpaw counter-puncher with Monroe's pedigree would provide a new challenge while he waits for the world's best fighters to take him on, and Monroe proved to be tough and elusive while hitting Golovkin regularly.

Yet Golovkin still delivered for his large fan base in Southern California, where he now lives with his family.

After Monroe tagged the champion repeatedly in the fourth, Golovkin's trainer, Abel Sanchez, implored his fighter to 'not show how tough we are. Let's start working.'

So Golovkin went back to work and finished with force.

'I think Gennady wanted to give the fans a little more value for their money, because the Rubio fight only lasted two rounds,' promoter Tom Loeffler said, referring to Golovkin's second-round stoppage of Marco Antonio Rubio in his California debut last autumn.

After a solid first round, Golovkin backed Monroe against the ropes in the second and knocked him flat with a textbook-perfect left hook to the head. Monroe wobbled while getting up slowly, and Golovkin put him back down moments later with a big right hand.

Monroe made it to the bell and even recovered to land several big shots in the fourth round, but Golovkin buckled his knees again in the fifth. Golovkin finished the sixth in style, pursuing a ducking Monroe around the ring until finally landing the knockdown punches in the sixth.

Monroe is defenceless as Golovkin connects with his face. He coped well with the new challenge of a southpaw counter-puncher

Monroe connects with Golovkin - his strongest round was the fourth but he was unable to sustain the pressure 

Monroe is sent flying to the canvas in one of two knockdowns in the second round of the contest after another powerful Golovkin hit

Monroe did manage to survive the count on this occasion but was no match for Golovkin's ferocious punches

Golovkin made the fight with Monroe when he couldn't entice bigger-name boxers into the ring, and he named names after the fight, calling out Miguel Cotto and Saul 'Canelo' Alvarez. Golovkin intends to fight twice more this year, staying busy and growing his own reputation as one of the world's pound-for-pound best fighters.

Golovkin wants to win every middleweight belt, He is the WBC's interim 160-pound champion and the mandatory challenger for Cotto's permanent belt, but Cotto is fighting Daniel Geale in New York next month.

If Cotto beats Geale, WBC President Mauricio Sulaiman said he would sanction Cotto's much-rumored fight with Alvarez in the fall as long as the winner agrees in writing to fight Golovkin next.

Gonzalez (43-0, 37 KOs) seized the chance provided by his first showcase on HBO with a masterful performance against Sosa, a talented veteran contender. 'Chocolatito' battered Sosa around the ring in the first round and dropped him three times in the second.

'I'm very happy with my performance,' Gonzalez said. 'He was a tough fighter, but my power was too much.'

A Golovkin uppercut with the right has Monroe grimacing as the Kazakh takes command of the contest in the second round

Golovkin continues to build his reputation as one of the world's best pound-for-pound fighters with this victory

A moment of close combat between Monroe and Golovkin during the fight, which was hosted by the revamped Forum venue in Los Angeles

Golovkin celebrates after his win and will wait with interest to see who his next opponent will be

Throwing sharp combinations and showcasing power in both hands, Gonzalez floored Sosa (51-9) twice with brutal right hands before finishing him with a multi-punch barrage against the ropes with 23 seconds left in the second round.

Gonzalez already sits high on most pound-for-pound lists, but had never received such a broadcast showcase due to networks' traditional reluctance to feature lighter weight classes.

Golovkin wore trunks trimmed with Los Angeles Lakers colors in the Forum for the second boxing show since the Madison Square Garden Co. bought and refurbished the arena as a venue for concerts and fights.

The fans arrived early and packed the arena in a remarkable turnout for both Golovkin and Gonzalez, who is wildly popular in Southern California's expatriate Nicaraguan community.

Roman Gonzalez of Nicaragua lands a punch on Edgar Sosa as the Nicaraguan shone on his HBO debut in Los Angeles

Gonzalez celebrates his victory over Sosa as he defended his WBC flyweight world title in California

Sosa made it only until the second round before he was stopped by the impressive Gonzalez