The Windsor Express topped London 110-100 on Wednesday to snap the Lightning's five-game win streak.
The Lightning scored a six-point lead over the Express in the first quarter, but Windsor tied things up at 62-62 by halftime.
Windsor jumped into the lead at the end of the third frame to make it 83-80 heading into the fourth. The Lightning weren't able to bounce back in the final quarter, losing with a ten point deficit.
Chad Frazier led Windsor with 28 points and six rebounds, while Shaquille Keith put up 25 points and had five rebounds.
Royce White was the top scorer for London with 28 points and 12 rebounds, while Mo Bolden and Garrett Williamson both added another 15 points each.
The Express are at home again on Friday to battle the KW Titans at 7pm. And then on Sunday, the Lightning take on the River Lions in Niagara at 2pm.