Kailub Russell's biggest test thus far in the 2015 Grand National Cross Country series might be Sunday at the Limestone 100.

He's been more or less untouchable through the first four rounds this year but not so much at Lawrence County Recreational Park in Springville, IN. He won it in 2012 but two years ago, he lost the lead after a big crash but managed to finish second. Last year, Russell went end-over-end in a spectacular crash, lost the lead and finished third. That also ended a three-race win streak.

"Last couple years haven't treated me too well here," said Russell, a MotoSport rider in the XC1 class. "But I do like this track and have been riding well lately so I'm looking forward to getting out there and trying to take another win."

On Sunday, he'll race for five straight wins to open the season and add to what is quickly becoming an insurmountable lead and a historic season for him. Josh Strang is trying to keep it close as he's ticked off four straight second-place finishes and trails by 20 points in the National Championship Standings. Grant Baylor is a distant third, 35 behind Strang and 55 back from Russell.

Crashes this year don't seem to deter Russell either as he hit the dirt on the opening lap in Round 2 but charged his way back up front. He's won every race by more than two minutes except for Round 4 which he beat Strang by 42 seconds. That win tied Strang's personal best of starting the season with four straight victories and also broke a tie with Fred Andrews on the all-time wins list. Now with 26 career wins, Russell is tied for third with Ed Lojak. Two more wins ties him with Juha Salinen's 2006 record of six straight wins to start a season.

Russell said he's been happy with how well he is executing his race so far every round.

Elsewhere, Brad Bakken who rides for MotoSport in the XC2 class will try and get back into the Top 10 after finishing 24th for his class last time around. He opened the year in ninth followed by two 10th place finishes.

In the Women's class, MotoSport rider Kacy Martinez finished second the last round ending a three-race win streak. The result repeated what happened last year when Jessica Patterson won her first of the year stopping Martinez's three race win streak. But, Martinez went on to win six straight in a dominating Championship run.

Racing starts at 1 p.m. (EST) Sunday at Lawrence County Recreation Facility, 99 Moore Lane in Springville, IN. Check the weekend schedule and directions for more information.

2015 GNCC Overall National Championship Standings

  1. Kailub Russell (120) - MotoSport rider
  2. Josh Strang (100)
  3. Grant Baylor (65)
  4. Thad DuVall (60)
  5. Chris Bach (55)
  6. Jordan Ashburn (44)
  7. Jason Thomas (38)
  8. Craig DeLong (36)
  9. Ryan Sipes (36)
  10. Trevor Bollinger (34)