Harris saved set point in the opening set to eventually beat the 22-year-old 7-6(8), 7-5 in an hour and 46 minutes.

The South African has now won three ATP Challenger titles this season, with Surbiton marking his first on grass throughout his career.

The former world No.31 has now won 16 of his last 17 matches on the ATP Challenger Tour and now heads to the Rothesay Open Nottingham looking to replicate Andy Murray’s back-to-back title run on the grass last year.

After a routine opening few games, Harris needed to fire three big serves to stave off a trio of break points midway through the opening set as Riedi looked the more settled of the two. The South African took a big fall at 0-15 down trailing 5-4 and faced break point again, but once again his serve dug him out of trouble.

In a tight set, largely dominated by the server, it was the opposite in the tie-break, with both players failing to serve out set points. As they battled on, it would eventually be Harris who reaped the rewards of his earlier persistence as Riedi fired long to give him a one set lead after 59 minutes.

Ultimately Harris proved the more clinical of the two in the big moments. The former US Open quarter-finalist saved another two break points at 5-5 in the second set – hitting his 17^th ace of the match – and took his one and only break point of the match on the final point.