Madrid — The men's 10.6km event, with temperatures at about nine degrees centigrade when the gun went, witnessed the dominance of the 24-year-old Chepkok, who grabbed his first win in Europe this winter after being runner-up at the opening leg of the IAAF Cross Country Permit series, on Spanish soil in Atapuerca last month.
Chepkok also managed his first success in Venta de Banos after finishing second two years ago.
The pace was pushed in the early stages of the race by Morocco's Spain-based Anouar Dabab, along with Spain's former European 3000m steeplechase champion Antonio Jiménez, the latter fresh from a gold medal by teams at last weekend's European Cross Country Championships, with the favourites, Chepkok and the current African 10,000m champion Kenneth Kipkemoi, running comfortably in the middle of a large main pack.
It was not until the fourth kilometre that Chepkok and Kipkemoi moved to the front and started to set a brisker pace.
The opening two 2100m laps were covered in 7:05 and 7:13 but by the end of the third circuit, completed in 6:58, Chepkok only had Kipkemoi and Jimenez for company.
With two laps remaining, the African duo - who both went under 27 minutes for the 10,000m for the first time at the Samsung Diamond League final in Brussels on 7 September - led by two seconds from Jimenez, who was five seconds ahead of the British pair of Patrick Martin and Adam Hickey.
The decisive move was made by Chepkok 25 minutes into the race when he decided to break away from the 28-year-old Kipkemoi. He opened a sizeable margin in a matter of just few metres.
Chepkok, whose previous lap had only taken 6:53, was eight seconds clear of Kipkemoi and 12 over Jiménez at the bell, while Spain's Daniel Santacruz had joined the Britons in the fight for the fourth place.
The leader didn't falter over the final couple of kilometres and romped home unopposed, 13 seconds ahead of Kipkemoi while Jiménez was another 25 seconds in arrears.
Behind the leading trio, Santacruz managed to get shake off the British pair to secure fourth place with Martin and Hickey four and eight second further back respectively.
Women's race - Cherono in a class of her own
Britain's Hannah Walker audaciously decided to go to the front over the opening kilometre of the 6.8km race, leading a pack which included Kenya's two-time IAAF World Junior Championships 3000m gold medallist Mercy Cherono, Eritrea's Nazaret Weldu, Morocco's Malika Asahssah, Italy's Nadia Ejjafini and Spain's Alessandra Aguilar.
The 21-year-old Cherono, who also won the 2010 World Cross Country Championships junior women's race, then opened up the throttle, going through the first two laps in 7:47 and 7:38 before reaching the bell seven seconds in front of Walker, who was making up for the slight disappointment of only finishing 12th in last Sunday's European Cross Country Championships when she was considered to be a potential medal contender.
In turn, Walker had nine seconds to spare of a chasing trio consisting of Aguilar, Asahssah and Kenya's Lydiah Chepkurui.
Cherono continued to pull away from her rivals on the last lap to win by the handsome margin of 23 seconds from Walker, while the Briton also had a hugely impressive run to come home 11 seconds in front of Weldu, who suffered her first loss this winter.
1. Vincent Chepkok (KEN) 35:20
2. Kenneth Kipkemoi (KEN) 35:33
3. Antonio Jimenez (ESP) 35:48
4. Daniel Santacruz (ESP) 36:02
5. Patrick Martin (GBR) 36:06
6. Adam Hickey (GBR) 36:12
7. Luke Cragg (GBR) 36:27
8. Philip Kiptoo (KEN) 36:30
9. Chema Martínez (ESP) 36:35
10. Francisco España (ESP) 36:35
1. Mercy Cherono (KEN) 24:33
2. Hannah Walker (GBR) 24:56
3. Nazaret Weldu (ERI) 25:07
4. Alessandra Aguilar (ESP) 25:09
5. Malika Asahssah (MAR) 25:11
6. Nadia Ejjafini (ITA) 25:35
7. Lydiah Chepkurui (KEN) 25:52
8. Cristina Jordan (ESP) 25:52
9. Rehima Jewar (ETH) 26:00
10. Katie Brough (GBR) 26:10