The Asian junior champion, seeded 14th at India's biggest domestic badminton event, needed 28 minutes to dismiss Rahul Patel 21-13, 21-13 on his way to the third round.
Sen, who will face Vipul Saini next, had reached the semi-finals in the previous edition and is looking to improve on that.
Former two-time champion Sourabh Verma of PSPB also began his campaign on a positive note with a commanding 21-10, 21-8 demolition of V.S. Jayapragasham.
The first day of the Nationals witnessed as many as 250 matches played on 9 different courts. The hosts had a lot to cheer about on Day 1 as five singles shuttlers from the state of Assam won their opening round matches. Iman Sonowal set up a clash with Sourabh Verma after outplaying J&K's Raghav Dogra 21-9, 21-3.
Assam's Orijit Chaliha lost to Mithun Manjunath 21-11;21-9 in the second round; earlier Orijit emerged a winner 21-14, 21-18 over Gujarat's Vishal Dave while Rituporna Bora defeated West Bengal's Anirban Mandal 21-5, 21-18.
In women's singles, Megha Bora Morchana had it easy against Nagaland's Ekumyala whom she beat 21-9, 21-14. Suzen Burhagohain advanced when Goa's Yasmin Syed retired trailing 2-3.
Among other matches, 2018 Ghana International winner Harsheel Dani won a blockbuster battle between two of India's rising stars when he prevailed over former World Junior Championships silver medallist Siril Verma 23-21, 21-17 to reach the third round.
Men's singles top seed Arintap Dasgupta completely outclassed Anay Shirpurkar 21-8, 21-5 while fifth seed Rahul Yadav Chittaboina needed 32 minutes to show the door to Karan Choudhary 21-17, 21-8. Sixth seed Aryamann Tandon blitzed past Bidyasagar Salam 21-6, 21-6 en route to Round 3.
Mixed doubles seventh seeds Manu Attri and Maneesha K hardly broke sweat in their 21-5, 21-6 destruction of Mohit Tiwari and Smirti Nagarkoti. Jammu and Kashmir's Raghav Dogra and Rupal Anand notched up a fine 21-12, 21-15 victory over Sikkim's Rewash Rai and Tashi Choden Gurung.
Shlok Ramchandran, who played a brilliant role in guiding the AAI to their Inter-Zonal triumph, hardly faced any hassle in his mixed doubles opener in partnership with Mithula UK. The two teamed up to beat Akshit Mahajan and Anupama Upadhyaya 21-12, 21-19 en route to the third round.
The preliminaries will continue till February 13 and will decide who all get to meet the top eight singles seeds who will begin their challenge directly from the pre-quarters. Similarly, in doubles, the top four teams have been exempted from playing until the quarters.
The seeds will be placed after the Super Draw is conducted on February 14. Saina Nehwal and PV Sindhu will be the top attractions in women's singles. In the absence of defending champion HS Prannoy and former winner Kidambi Srikanth, BWF World Tour Finals semi-finalist Sameer Verma will be the biggest name in men's singles.