Irish rider Eugene Laverty produced a measured ride to claim the second race in the Assen round of the World Superbike Championship.
In a classic nail-biter at the Assen TT circuit, Laverty had just enough in hand to defeat Race 1 winner Sykes with Loris Baz holding out Jonathan Rea to claim third.
At the start the 27-year-old Huddersfield rider Sykes made a lightning start but was closely followed by Laverty as the pair began what would be a race-long dogfight.
In the opening laps Sykes and Laverty managed to gain a break on the field with the latter putting pressure on the leader.
By lap 15 of the 22-lap race Laverty began sizing up Sykes who was beginning to struggle for rear grip on his Kawasaki.
With three laps to go Laverty grabbed the lead from Sykes and quickly began to forge clear. But his mini break was not to last.
Sykes began to claw his way back and loomed as a chance to grab the lead back before having a lunge on the inside into the final corner to narrowly miss out on capturing a double.
Earlier Sykes was untroubled to win the opening race, claiming the sixth win of his career.
The Pata Honda rider Rea claimed second after moving past Sylvain Guintoli (Aprilia) at turn 13.
Laverty, on the second Works Aprilia, was in a three-way battle for second spot but was forced to settle for fourth place behind Guintoli.
Baz (Kawasaki Racing Team) finished fifth with Davide Giugliano (Althea Racing Aprilia) sixth who then slid off the track at turn two in the second race with his bike spectacularly catching fire in the incident.
There was no luck for the BMW rider Chaz Davies who lined up on the last row of the grid after his crew were forced to hastily repair his BMW S 1000 RR after a warm-up crash.
After a good start Davies managed to finish the first 22-lap race in seventh place.
Guintoli leads the Championship going into the Monza round from May 11-12 on 111 points from Laverty, Sykes and Davies who share second place on 83 points.