Andre Ward has stretched his unbeaten professional record to 26 fights by defeating Edwin Rodriguez on points at Citizens Business Bank Arena, California.
The Dominican weighed in two pounds over the 168lbs limit yesterday, which saw his chance of winning the American's WBA super middleweight title go up in smoke.
The fight was scrappy for the first couple of rounds, which came to a head in the fourth round when referee Jack Reiss stepped in to separate a clinch and was caught by a left hook from Rodriguez.
After taking a few seconds to himself, Reiss returned to read the riot act and deduct two points from both men.
Ward began to dominate following that exchange and pulled away on the scorecards with ease to earn the judges' vote with scores of 118-106, 117-107 and 116-108.
The fight is only the 28-year-old's second since defeating Carl Froch in Atlantic City nearly two years ago, with his last being a 10th-round stoppage of Chad Dawson in September 2012.