Action Express Racing pairing Joao Barbosa and Darren Law scored their second win of the Rolex Series season at the Sahlen's Six Hours of The Glen, lifting the team to the top of North American Endurance Championship (NAEC) and Law into contention for the drivers' title in the process.

Though it was Law – who is now just seven points from the points' leaders – and the team who reaped the benefits in the standings it was Portuguese Barbosa who secured the victory with an aggressive move at turn seven on the longer layout at Watkins Glen International.

Having passed Sebastien Bourdais for second shortly after a final restart Barbosa in the #9 Chevrolet Corvette DP was part of a line of as many as the half dozen the leading Daytona Prototypes covered by a matter of seconds with just 20 minutes of the race remaining, chasing down Alex Gurney in the GAINSCOBob Stallings Racing Corvette DP.

The decisive moment came when the DP and overall lead came upon the GT leaders – having a battle all of their own.

Gurney and Barbosa came up to Emil Assentato in the Aim Autosport/FXDD Ferrari – running third in GT – as they approached turn seven. Gurney passed the Ferrari but left a gap on the inside of the turn, perhaps over cautious of being hit by the slower car. However, it was Barbosa rather than Assentato who filled the gap, slicing between the two cars to take the inside line. Gurney tried to close the gap, but could only make side to side contact with Barbosa before having to give up the position.

Barbosa was allowed to escape further a lap later when a battling Bill Auberlen and Robin Liddell, fighting to the GT lead, conspired to split Barbosa and Gurney, allowing the former to establish a crucial three second lead as the minutes ticked down.

Impressively Gurney – who is still to win this season – fought back to within touching distance of Barbosa in just a few laps, though again slower traffic conspired to slow the chasing driver – this time a Porsche forcing him to lift off the throttle around the outside of turn five. It was just a lift, but as Gurney clawed back to just 0.238 seconds when he and Barbosa swept beneath the checkered flag, it was all that was needed to decide the race.

Behind the DP fight Robin Liddell held off Turner Motorsport BMW driver Auberlen for Stevenson Motorsport's first win of the season. The pair had been close throughout the final run – following the final caution for Martin Ragginger's stopping of the fiery Burtin Racing Porsche GT3 – initially fighting for second in class behind the Brumos Racing Porsche of Leh Keen.

However, Keen had to made a final stop for fuel and Auberlen and Liddell raced downhill into turn one side-by-side in what was suddenly a fight for the class lead. Auberlen looked outside of the #75 Camaro, but Liddell defended the place, easing his rival wide, over the kerb and onto the tarmac run-off, allowing him to pull a car length ahead before Auberlen could regain the track before the climb up to the Esses.

Liddell had had to fight back from an earlier penalty after he was adjudged to have jumped a restart when he crossed the line overlapping with Stevenson Motorsport's other Camaro. That sister team – the #75 car started from class pole position by Jordan Taylor was a factor in the class lead battles throughout the race, leading from pole and for large parts of the opening half of the race. The team – Taylor joining Matt Bell and Ronnie Bremer for the race – eventually completed the top five in class, behind the Extreme Speed Motorsports and FXDD Ferraris, Assentato and Jeff Segal keeping their points lead in the championship by rounding out the class podium.

Liddell's victory – with co-driver John Edwards – also lifted Stevenson to the top of the NAEC standings in the GT class, leaping ahead of the Magnus Racing team – who started the race in the lead thanks to the Rolex 24 victory. Their time at Watkins Glen, however, was to be much less successful John Potter pulling the car off with a fire in the cockpit after just 30 minutes of racing.  

The fire in the #44 Porsche brought out the first of six caution periods. In the ensuring pitstops Barbosa took the lead from Scott Pruett who had started from pole in Chip Ganassi Racing's BMW-Riley. Pruett and Memo Rojas dominated the first half of the race, combining to lead 70 of the 93 laps completed in the first half of the race.

The pair lost the lead for the final time in the flurry of green flag stops shortly before half distance to Ryan Dalziel and the Starworks Motorsport team. The #01 team then lost further time, having to change a leaking radiator. Though the team – multiple champions in the Rolex Series – completed the change with a minimum of lost time – both drivers reported a loss of power from the BMW engine during the second half of race, potentially as a result of overheating.

Pruett and Rojas were still able to finish fourth behind the Starworks car of Dalziel, Bourdais and Enzo Potolicchio. Behind the Ganassi car, but still on the lead lap at the end of the race, were the Spirit of Daytona and Michael Shank Racing entries.

Both cars had endured separate incidents during the race. Richard Westbrook at the wheel of Spirit of Daytona's Corvette DP lost time with a punctured left-rear tyre after making contact with a GT car during the third hour, though he managed to lose a lap to the leaders as he limped back to the pits.

Earlier in the race John Pew had spun Michael Shank Racing's Ford-Riley at the inner loop, stalling to bring out the race's second caution and initially losing a lap – though a decision not to pit under the following caution erased the deficit.

Though Pew and Ozz Negri rallied back to the sixth place – despite Negri spinning once himself – they lost the NAEC lead to Action Express Racing, who as well as scoring maximum points for the race win, also banked the points on offer for leading after three hours, eeking out their fuel mileage for an extra lap compared to their rivals to lead over the three hour mark.

Meanwhile, Pruett and Rojas maintain the lead in the full Rolex Series standings, though now just three points ahead of Dalziel and Potolicchio.

Elsewhere in DP SunTrust Racing's awful run continued with another retirement. At the first restart Max Angelelli had made apparently light contact with David Donahue's #5 Action Express car, though debris from the incident was significant enough for the yellows flag to fly once more.

But as the race the progressed, and once a new rear bodywork section had been fitted to the SunTrust car, it became apparent that the contact was not as minor as it had first appeared, suspension damage leading to retirement.