Alastair Cook expects Joe Root to go "miles past" his record for the most Test runs scored by an England batter after the former captain reached the 10,000 landmark at Lord's.
Playing his first game for his country since stepping down as skipper, Root claimed the man of the match award for his magnificent unbeaten 115 in a five-wicket win over New Zealand.
He was brilliantly supported by Ben Foakes (32 not out) in an unbroken stand of 120 that gave England a winning start to a new era with Ben Stokes as captain and Brendon McCullum head coach.
Root's 26th Test century made him only the second England player to score 10,000 runs in the longest format after Cook, and only the 14th from any nation.
At 31 years and 157 days, he reached the milestone at exactly the same age that his former team-mate Cook achieved the feat.
Root is 2,457 runs shy of the tally of 12,472 Cook racked up in his outstanding Test career and the former skipper says only injury can prevent him from beating his record.
"Barring injury, he'll go miles past my record," Cook told BBC Sport.
"He is so hard to tie down. I had to grind my way to 30, it always took me what felt like two hours. Because Joe has got so many low-risk scoring options, pretty much through 360 degrees, he will often get to 30 off 40 balls."
Cook, who ended his international career aged 33, rates Root as the best England batter he has witnessed.
"He is a pleasure to watch, the most complete England batsman I have seen," he added.
"The person who could play the most incredible innings was Kevin Pietersen, but for the most complete batsmen in all three forms, it's Root. His consistency is incredible."
England and New Zealand start the second match of the series at Trent Bridge on Friday.