Luxembourg's Gilles Muller out-aced the record-breaking Ivo Karlovic in a landmark battle of the big-serving veterans to lift the grasscourt title in Den Bosch on Sunday.

Croatia's 38-year-old Karlovic became the first man to ever pass the milestone of 12,000 aces as he blasted down another 19 yet he still could not stop his 34-year-old opponent coming out on top 7-6(5), 7-6(4) in the Wimbledon warm-up tournament.

With a combined age of 72, it was the oldest singles final on the ATP World Tour since Hong Kong in 1976 when 42-year-old Ken Rosewall defeated 30-year-old Ilie Nastase.

Croatia's 38-year-old Karlovic became the first man to ever pass the milestone of 12,000 aces

ATP ACE LEADERS Ivo Karlovic - 12,003 Goran Ivanisevic - 10,131 Roger Federer - 9,940 Andy Roddick - 9,068 John Isner - 9,60 Advertisement

Earlier, Estonia's Anett Kontaveit, one of the rising talents of the WTA tour, won her first tour title in the women's final, beating Russian Natalia Vikhlyantseva 6-2 6-3.

Muller, Luxembourg's best-ever player, has enjoyed a remarkable season, winning his second title of the year here after previously never having managed to earn one in 13 years of trying.

The left-hander even blasted 22 aces to outperform Karlovic, the most prolific purveyor of aces the game has ever seen, winning two tiebreaks after neither man had enjoyed even the sniff of a break point in the one hour 35 minute contest.

But Karlovic could not seal his first ATP title of the year after falling to a straight-set defeat

Luxembourg's Gilles Muller hit 22 aces en route to claiming his second ATP title of 2017

The 21-year-old Kontaveit, who had already reached one WTA final and beaten world number one Angelique Kerber this season, overcame a dip in concentration at the start of the second set to earn her victory in just under an hour and a quarter.

The 20-year-old Vikhlyantseva, another promising talent, was outplayed in the opening set but after breaking to take a 3-1 lead in the second, Kontaveit moved into overdrive to halt the comeback swiftly and win the next five games.

The victory will shoot the young prospect from Tallinn from world number 49 to a new career-high of 36 when the rankings are announced on Monday.