After building up an undefeated record on the Dutch kickboxing and Muay Thai scene, Henri van Opstal challenged Martin Akhtar for the WMC World Junior Welterweight (-63.5 kg/140 lb) Championship in Sweden, losing for the first time in his professional career by decision.
He made his K-1 debut at the K-1 World MAX 2010 West Europe Tournament in Utrecht, Netherlands on March 21, 2010, where faced Robin van Roosmalen in the quarter-finals.
He easily outclassed Rhyse Saliba in the quarter-finals, knocking him down inside the opening thirty seconds and causing problems with his boxing throughout the match and winning by unanimous decision.
[3] Van Opstal rematched Harut Grigorian at War of the Ring in Amsterdam, Netherlands on February 2, 2011, losing by unanimous decision but he soon made a successful return to Japan where he would go on to have a string of wins over some of the nation's top middleweights and earn the moniker of "the Japanese Killer".
[9] In the main event of REBELS.12 & It's Showtime Japan Countdown-2 in Tokyo on July 29, 2012, van Opstal improved to 4-0 over Japanese competition with a majority decision win over Hiroki Nakajima.
Van Opstal stopped Suzuki for a second time, dropping him twice in under a minute in round one and forcing the referee to call the fight off, setting up a match with his stable mate and mentor Andy Souwer in the final.
[14] Van Opstal lost to a Japanese foe for the first time at Shootboxing 2013: Act 1 on February 22, 2013, when he dropped a close majority decision to Yoshihiro Sato.
Petrosyan caused damage with low kicks over the course of the fight and, after being thrown to the canvas a few times, van Opstal found it increasingly difficult to get up due to his legs being battered and his corner threw in the towel at the end of the third round.