Judging by some of the performances from this weekend, Saturday’s NEC cross-country championships look to be a wide open affair.The Peabody and Marblehead boys squads were in separate competitions this weekend but each put up standout performances.The Tanner boys and girls were at Franklin Park in Boston as a part of the CM Invitational. The boys were a solid third as a team, led by Marcelo Rocha’s third place finish (16:15). Teammates Jason Karakaedos (16:38) and Riley Dowd (16:46) were ninth and 12th respectively.On the girls side, the highest placing local finisher was Lynnfield senior Tia Patterson, who turned in an outstanding third place (20:06). Peabody’s Lauren Barrett finished fifth (20:35) with Fenwick’s Sydney Packard in seventh (20:39) and Peabody’s Mackenzie Picardy in 17th (21:41). The Tanners were third as a team while Fenwick was seventh.A short jaunt down the Southeast Expressway, Marblehead’s Andrew Ernst added another notch to his resume this season as he ran down Bromfield’s Nick Steele in the final meters to win the Division 2 boys race at the Bob McIntyre Twilight Invitational at the Barnstable Fairgrounds.Ernst’s winning team was 16:01.19 with Steele finishing in 16:01.77. Jared Kokinos was 15th overall for Marblehead (17:01.68).