The Jets, ninth in the table, led 25-10 after 12 minutes against the league leaders, who are still adjusting to the fact that they will not add the Cup to the NatWest Trophy, which they took from Guildford last month.
Cheshire's American Tyrone Thomas and John Mayr made the early impact alongside Dave Gardner and Craig Nuttall, before Tigers' American pairing of Nigel Lloyd and Lester James stemmed the flow and narrowed the Jets' lead to 31-30 at the interval.
As Tigers edged ahead at 50-43, Cheshire's coach, Mike Burton, earned two technical fouls for arguing with the officials and handed Thames Valley another three points as they pulled away to win 79-56.
A run of three victories by Derby Bucks ended in tame surrender to second-placed Worthing Bears, who won 98-72 with 30 points from Colin Irish and 22 from his fellow England international, Mark Hubbard.
Derby's brief moment of inspiration followed Carl Mitchell blocking Alan Cunningham's shot and setting up Kurt Samuels for a three-point play which tied the scores at 16-16.
But the Bears soon pulled ahead, despite the American, Kalpatrick Wells, struggling with foot and leg injuries.
London Towers stay third after beating the bottom club, Sunderland Saints, 93-66, but fourth- placed Guildford's win on Friday night over Birmingham, by 101-79, was marred by injury to their American, Lorenzo Duncan.
Duncan, who scored 24 points in support of 27 from the England centre Trevor Gordon, suffered an ankle strain but should be fit for next weekend's visit to Worthing. Guildford also meet them on 28 February in the National Cup final at the Doncaster Dome.
Doncaster Panthers booked their place in the National Trophy final, which is also to be played at the Dome, their home venue, by defeating Ware Rebels 96-71. Tony Holley led Doncaster's scorers with 26 points.Reuse content