The TFC coach, whose team has played 11 games since June 16, emptied his bench on Saturday against the English Premier League outfit that was also without a number of its stars in an exhibition match at Rogers Centre.
"You've got to temper your thoughts with where Liverpool are at, the squad that they brought over, but all you can do is your best and I thought we did well under the circumstances," Mariner said. "Let's not get carried away. If Liverpool bring their first squad and they're further on in their pre-season or the season, they're a top-class team with top-class players."
Among the absentees from the Liverpool lineup were captain Steven Gerrard and England teammates Andy Carroll and Glen Johnson, who sat out because of rules related to rest following international tournaments as the club began its pre-season North American tour under new manager Brendan Rodgers.
"It was a brilliant day out. I think both teams got what they needed out of the game," Toronto FC midfielder Terry Dunfield said. "I think both teams in each half gave a good account of themselves. There's no hiding that our schedule has been brutal of late."
Mariner, who is now 4-2-5 with Toronto FC since taking over for the fired Aron Winter last month, said more important than the result is the experience his players will take away from a game against one of the biggest clubs in the world.
"It lets all the players, either the senior players or the academy players, to realize that they're not that far away from competing with some very, very good players," Mariner said. "It's a wonderful educational experience for everybody."
Liverpool youngster Adam Morgan scored in the 69th minute to cancel out Quincy Amarikwa's opener for Toronto FC 11 minutes earlier.
The 18-year-old Morgan tapped a shot past Quillan Roberts from a yard out after the TFC goalkeeper could only get a piece of Raheem Sterling's strike.
Amarikwa, making his first appearance for Toronto after being acquired from New York earlier in the day, buried a rebound past Liverpool goalkeeper Peter Gulacsi for an MLS side that was full marks for the draw and continued its resurgence under Mariner.
"As a forward you're always envisioning yourself scoring a goal," said the 24-year-old Amarikwa. "I'm excited to be here, excited to get the opportunity to show what I can do."
Mariner, who also acquired striker Eric Hassli in a trade with Vancouver on Friday night, was pleased with Amarikwa's debut.
"He's a small guy but he's very strong and it was a classic centre forward's goal — always follow the shot in," Mariner said. "He did that and I'm very happy for him."
Liverpool fans, many of them in jerseys, chanted and sang songs familiar to the terraces at Anfield beginning in the warmups, including a stirring rendition of the club's anthem "You'll Never Walk Alone." Supporters of the 18-time English league winners unfurled numerous banners, including one honouring the Hillsborough disaster in which 96 fans were crushed to death in 1989.
But the game played on a temporary grass surface in front of 33,087 fans failed to live up to the hype in the first half.
Toronto FC, which started the game with a number of regulars in the lineup, including captain and midfielder Torsten Frings, striker Ryan Johnson and defender Richard Eckersley, did well to keep up with Liverpool in the first half.
Liverpool, meanwhile, with a starting 11 that included 16-year-old Jordan Ibe, failed to assert itself in the early going.
Toronto FC had the game's first chance in the seventh minute when Johnson fired a shot off a pass from Luis Silva that Liverpool goalkeeper Brad Jones had to stretch for.
Liverpool had a shout for handball in the 34th minute when Jose Enrique's shot was blocked by a TFC defender in the area.
Liverpool made 11 substitutions at halftime, while Toronto FC made 10. Liverpool introduced former England international Joe Cole and defender Martin Skrtel, while Brazilian midfielder Lucas came on as a substitute later in the half for his first action since tearing his anterior cruciate ligament last season.
Despite lineups that included few regulars and some players from each club's youth system, the moves breathed life into the game as Amarikwa and Morgan traded goals in a second half that fans enjoyed much more than the first.
Liverpool pressed for the win and was awarded a freekick in the 88th minute, but Cole's delivery from the edge of the penalty area was woeful and went out of play.
Liverpool, which finished a disappointing eighth in the Premier League last season, continues its pre-season schedule on Wednesday at Boston's Fenway Park against Italy's A.S. Roma before taking on English rivals Tottenham on July 28 in Baltimore.
Despite the lack of star power, Dunfield says the result will show Toronto went toe-to-toe with one of the game's most storied teams.
"We played Liverpool Football Club today, drew 1-1 with them and probably had the better chances as well," he said. "We'll take a lot from that."
Notes: The roof at Rogers Centre was open to start the game but was closed early in the second half. ... Liverpool starting goalkeeper Pepe Reina (Spain), striker Fabio Borini (Italy) and midfielders Jordan Henderson (England) and Stuart Downing (England), who also played at Euro 2012, also did not make the trip to Toronto. ... Liverpool strikers Craig Bellamy (Britain) and Luis Suarez (Uruguay) are scheduled to play for their respective countries at the London Olympics and not on the North American tour.