Adam O'Brien took 4-40 while father and son Kashif and Danial Ibrahim took two wickets each. Nomads were cruising at 83-2 before spinner Rigg got into his stride and ran through the middle and lower order.
Three Bridges (258-4) had a successful run chase against East Grinstead (257-7).
Leo Cammish continued his good form with 101 and he put on 116-1 with Will Adkin, who hit 61. In the reply, Connor Golding (82), Will O'Donnell (59), skipper Joe Walker (69 not out) and Luke Bellars (39 not out) saw Bridges home.
Roffey (255-4 dec) for back to winning ways with a comprehensive 134 run win over Haywards Heath (121 all out).
Robot Jagota (82) and Matt Davies (72 not out) were the stars with the bat for Rofdey before Luke Barnard took 5-22.
Eastbourne (215-9) also got back to winning ways with a 46-run over Middleton (169 all out).
Jacob Smith (54) and Malcolm Johnson (60) lead the way with the bat for Eastbourne while Mahesh Rawat took 5-46 for Middleton. In reply, Joe Pocklington toon 4-39 and Smith 3-35.
Harry Finch hit an unbeaten 114 as Hastings Priory (195-9) drew with Cuckfield (167-6). Josh Hayward took 4-70 for Cuckfield. Ollie Graham hit 51 in Cuckfield's reply.
Nomads remain top, but Roffey, Grinstead and Bridges are hot on their heels.
In Division two, Billingshurst (145-7) enjoyed another win with a three wicket win against Chichester Priory Park (141 all out) and it was that man Shakeem Clarke who starred again with 5-30. Thomas Alexander took 4-26. Amit Sambhi took 5-47 for Chichester.
Nick Oxley took 7-29 and hit 45 as Horsham (98-4) beat Roffey 2nd XI (97 all out).
James Hockley took 5-9 as Mayfield (201-9) beat leaders Bognor (143 all out). Rob Sharma hit 69 for Mayfield.
Toby Pullan took 5-8 and hit an unbeaten 51 for St James's Montefiore (68-0) cruised to a 10-wicket win against Burgess Hill (67 all out).
Owen Kernan took 5-13 as Preston Nomads (71-2) hammered Lindfield (70 all out).
Division 3 West: Rilwan Mohamed 5-56 for Slinfold. Peter Cotterill 5-53 for Pagham. Matt Machan 228 and Martyn Swift 8-20 for West Chiltington 403-6. Goring 56 all out. 350 run victory.
Division 3 East: Nimanda Madushanka 122 not out and William Goss 5-32 for St Peters. Daniel Stickels 101 and Dan Seabrook 100 for Rye.
Division 4 West: Christopher Barnett 123 not out for Steyning
Division 4 East: Tom Beswick 117 not out for East Grinstead 2nd XI. Ed Wright 5-5 for Rottingdean.
Division 5 Central: Freddie Piper 100 for St James's 2nd XI. Ben Chapman 134 for Fletching. Matt Jones 6-37 for Haywards Heath 2nd XI.
Division 5 East: Ollie McDonald 134 fir Hailsham.
Division 6 East: Bradley Ayres 6-28 for Crowhurst Park 2nd XI.
Division 7 West: Tommy Dunger 6-17 for Pulborough. Oliver Hemsley 5-15 for Littlehampton 2nd XI.
Division 7 East: Paul Barnett 7-17 for Iden. Andy Bird 5-13 for Firle.
Division 8 East: Redding Barnes 132 for Buxted Park 2nd XI.
Division 9 Central: Scott Clark 100 for Lindfield 3rd XI. Gavin Hills 5-4 for St Andrews as they bowled Keymer out for 29.
Division 10 West: Bhavesh Prabhakar 5-31 for Rustington 2nd XI.
Division 10 Central: Howard Johnson 6-47 for Edenbridge 2nd XI.
Division 10 East: Paul Nice 134 for Robertsbridge 2nd XI
Division 11 Central (North): Aaron Gee 144 from 99 balls for Felbridge and Sunnyside 3rd XI. Joe Russell 105 not out for Mid Sussex Heathens. Anuk Perera 6-12 for Haywards Heath 3rd XI.
Division 11 East (North): Charlie Grave 108 not out for Chiddingly 2nd XI. Iain Bell 5-11 for Wadhurst.
Division 12 West (North): Andy Parsons 127 for Slinfold 3rd XI.
Division 12 Central (North): Stephen Fallowell 5-21 for Lingfield 4th XI. Juju James 5-46 for St Andrews 3rd XI.
Division 12 Central (South): Jack Easton 6-22 for Denton 2nd XI.