Cardiff went ahead 72-71 with 65 seconds to play but after Doncaster's American, Tony Holley, missed with his shot, Penny grabbed the rebound before the Cardiff defence reacted and scored. Holly led Doncaster's scorers with 26 points.
The First Division leaders, Thames Valley Tigers, won 86-69 at Birmingham Bullets to stay ahead of Worthing Bears, but the third-placed London Towers survived at Cheshire only after the Jets' American, Doug Herring, fouled out in the 18th minute.
The Jets, bottom of the division but recently strengthened by the signing of Herring and Tyrone Thomas, went ahead 67-66 with two minutes to play on two free throws from John Mayor.
Then Herring fouled out, earning a technical foul in the process for arguing, which sent Andrew Bailey to the free-throw line to score four successive points to put London on course for a 75-70 win.Reuse content